Science.gov

Sample records for nondestructive technique survey

  1. Nondestructive Technique Survey for Assessing Integrity of Composite Firing Vessel

    SciTech Connect

    Tran, A.

    2000-08-01

    The repeated use and limited lifetime of a composite tiring vessel compel a need to survey techniques for monitoring the structural integrity of the vessel in order to determine when it should be retired. Various nondestructive techniques were researched and evaluated based on their applicability to the vessel. The methods were visual inspection, liquid penetrant testing, magnetic particle testing, surface mounted strain gauges, thermal inspection, acoustic emission, ultrasonic testing, radiography, eddy current testing, and embedded fiber optic sensors. It was determined that embedded fiber optic sensor is the most promising technique due to their ability to be embedded within layers of composites and their immunity to electromagnetic interference.

  2. Nondestructive testing techniques

    NASA Astrophysics Data System (ADS)

    Bray, Don E.; McBride, Don

    A comprehensive reference covering a broad range of techniques in nondestructive testing is presented. Based on years of extensive research and application at NASA and other government research facilities, the book provides practical guidelines for selecting the appropriate testing methods and equipment. Topics discussed include visual inspection, penetrant and chemical testing, nuclear radiation, sonic and ultrasonic, thermal and microwave, magnetic and electromagnetic techniques, and training and human factors. (No individual items are abstracted in this volume)

  3. Nondestructive evaluation technique guide

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1973-01-01

    A total of 70 individual nondestructive evaluation (NDE) techniques are described. Information is presented that permits ease of comparison of the merits and limitations of each technique with respect to various NDE problems. An NDE technique classification system is presented. It is based on the system that was adopted by the National Materials Advisory Board (NMAB). The classification system presented follows the NMAB system closely with the exception of additional categories that have been added to cover more advanced techniques presently in use. The rationale of the technique is explained. The format provides for a concise description of each technique, the physical principles involved, objectives of interrogation, example applications, limitations of each technique, a schematic illustration, and key reference material. Cross-index tabulations are also provided so that particular NDE problems can be referred to appropriate techniques.

  4. Nondestructive Acoustic Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Schmitz, Volker

    Acoustic imaging techniques are used in the field of nondestructive testing of technical components to measure defects such as lack of side wall fusion or cracks in welded joints. Data acquisition is performed by a remote-controlled manipulator and a PC for the mass storage of the high-frequency time-of-flight data at each probe position. The quality of the acoustic images and the interpretation relies on the proper understanding of the transmitted wave fronts and the arrangement of the probes in pulse-echo mode or in pitch-and-catch arrangement. The use of the Synthetic Aperture Focusing Technique allows the depth-dependent resolution to be replaced by a depth-independent resolution and the signal-to-noise ratio to be improved. Examples with surface-connected cracks are shown to demonstrate the improved features. The localization accuracy could be improved by entering 2-dimensional or 3-dimensional reconstructed data into the environment of a 3-dimensional CAD drawing. The propagation of ultrasonic waves through austenitic welds is disturbed by the anisotropic and inhomogeneous structure of the material. The effect is more or less severe depending upon the longitudinal or shear wave modes. To optimize the performance of an inspection software tool, a 3-dimensional CAD-Ray program has been implemented, where the shape of the inhomogeneous part of a weld can be simulated together with the grain structure based on the elastic constants. Ray-tracing results are depicted for embedded and for surface-connected defects.

  5. Nondestructive Technique To Assess Embrittlement In Steels

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.; Yost, William T.; Cantrell, John H.

    1990-01-01

    Recent research at NASA Langley Research Center led to identification of nondestructive technique for detection of temper embrittlement in HY80 steel. Measures magnetoacoustic emission associated with reversible motion of domain walls at low magnetic fields. Of interest to engineers responsible for reliability and safety of various dynamically loaded and/or thermally cycled steel parts. Applications include testing of landing gears, naval vessels, and parts subjected to heat, such as those found in steam-pipe fittings, boilers, turbine rotors, and nuclear pressure vessels.

  6. Nondestructive evaluation techniques for enhanced bridge inspection

    SciTech Connect

    Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.

    1993-10-01

    Nondestructive evaluation of bridges is a critical aspect in the US aging infrastructure problem. For example in California there are 26,000 bridges, 3000 are made of steel, and of the steel bridges, 1000 are fracture critical. California Department of Transportation (Caltrans), Federal Highway Administration, and Lawrence Livermore National Laboratory (LLNL) are collaborating to develop and field NDE techniques to improve bridge inspections. We have demonstrated our NDE technologies on several bridge inspection applications. An early collaboration was to ultrasonically evaluate the steel pins in the E-9 pier on the San Francisco Bay Bridge. Following the Loma-Prieta earthquake in 1989 and the road way collapse at the E-9 pier, a complete nondestructive evaluation was conducted by Caltrans inspectors and several ultrasonic indications were noted. LLNL worked with Caltrans to help identify the source of these reflections. Another project was to digitally enhance high energy radiographs of bridge components such as cable end caps. We demonstrated our ability to improve the detection of corrosion and fiber breakage inside the end cap. An extension of this technology is limited view computer tomography (CT). We implemented our limited view CT software and produced cross-sectional views of bridge cables from digitized radiographic films. Most recently, we are developing dual band infrared imaging techniques to assess bridge decks for delaminations. We have demonstrated the potential of our NDE technology for enhancing the inspection of the country`s aging bridges.

  7. Nondestructive evaluation techniques for thick concrete

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight A.

    2017-04-01

    The use of concrete structures has made its long-term performance crucial for the safe operation of commercial nuclear power plants (NPPs), especially with license period extensions to sixty years and possibly beyond. Unlike most metallic materials, reinforced concrete used in NPPs is a heterogeneous material, a composite with a low-density matrix, a mixture of cement, sand, aggregate and water, and a high-density reinforcement, made up of steel rebar or tendons. This structural complexity makes nondestructive evaluation (NDE) a challenging task. While the standard Synthetic Aperture Focusing Technique (SAFT) is adequate for many defects with shallow concrete cover, some defects that are located under deep concrete cover are not easily identified using the standard SAFT techniques. For many degradation mechanisms, particularly defects under deep cover, the use of advanced signal processing techniques is required. A variety of test specimens were evaluated using several advanced signal processing techniques ranging from a large specimen representative of a NPP containment wall (2.134 m x 2.134 m x 1.016 m) with twenty embedded defects, to specimens with accelerated alkali-silica reaction (ASR), and specimens with freeze-thaw damage. The first technique examined in this paper generates frequency banded SAFT reconstructions using wavelet packet decomposition and reconstruction. While the frequency banded SAFT reconstructions show a vast improvement over the standard SAFT for defects under deep cover, a second technique, Model Based Iterative Reconstruction (MBIR), has been initiated to address the limitations of the frequency banded SAFT (such as multiple reflections for a single defect).

  8. Vibrothermography: Investigation and Development of a New Nondestructive Evaluation Technique.

    DTIC Science & Technology

    1983-01-01

    8217! _"t _U1 IV~ V I Vibrothermography: Investigation and Development of a New Nondestructive Evaluation Technique FINAL REPORT Edmund G. Henneke, I Kenneth...understanding of the mechanisms involved in this process. Vibrothermography is a nondestructive inspection technique based upon the utilization of this...phenomenon. It has been found that this technique has DD W,.13 COMMN OF I NOV 651 IS 9METE SECUmFTY CLASSIFICATION OP TIMIS PAGE (When Date 61ard 20

  9. Techniques for enhancing laser ultrasonic nondestructive evaluation

    SciTech Connect

    Candy, J; Chinn, D; Huber, R; Spicer, J; Thomas, G

    1999-02-16

    Ultrasonic nondestructive evaluation is an extremely powerful tool for characterizing materials and detecting defects. A majority of the ultrasonic nondestructive evaluation is performed with piezoelectric transducers that generate and detect high frequency acoustic energy. The liquid needed to couple the high frequency acoustic energy from the piezoelectric transducers restricts the applicability of ultrasonics. For example, traditional ultrasonics cannot evaluate parts at elevated temperatures or components that would be damaged by contact with a fluid. They are developing a technology that remotely generates and detects the ultrasonic pulses with lasers and consequently there is no requirement for liquids. Thus the research in laser-based ultrasound allows them to solve inspection problems with ultrasonics that could not be done before. This technology has wide application in many Lawrence Livermore National Laboratory programs, especially when remote and/or non-contact sensing is necessary.

  10. Nondestructive assay (NDA) techniques and procedures

    SciTech Connect

    Not Available

    1994-05-01

    Report No. 4 is precursory to Report No. 5 {open_quotes}Determination of the Quantity and Locations of the Pu Currently Retained in the Cimarron Fuel Plant Systems{close_quotes} which will be presented upon completion of the decontamination of the Cimarron Plutonium Fuel Fabrication Facility. This report presents the Non-Destructive Assay (NDA) procedures which were developed and used by Sequoyah Fuels Corporation (successor to Kerr-McGee Nuclear Corporation) to measure equipment hold-up of plutonium materials for inventory purposes during operation of the plant. These procedures are also used to measure plutonium contamination on the equipment removed from the Material Balance Areas (MBA`s) during final decontamination. Report No. 5 will compare the measurements taken during this final decontamination period to previous inventory hold-up measurements, the date will be statistically analyzed, and a long-term assessment of the performance of the NDA equipment will be described.

  11. Non-destructive techniques based on eddy current testing.

    PubMed

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future.

  12. Non-Destructive Techniques Based on Eddy Current Testing

    PubMed Central

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  13. Nondestructive testing by ESPI and quasi phase shift gradient technique

    NASA Astrophysics Data System (ADS)

    Pang, Linyong; Wu, Xiaoping

    1996-09-01

    A new nondestructive testing (NDT) technique, which is based on Electronic Speckle Pattern Interferometry (ESPI) and digital image processing with quasi phase shift and gradient technique, is presented. A simple phase reduction algorithm is developed, which replaced an accurate phase shifter. Compared with other phase shift techniques, this method is insensitive to environmental vibration and air disturbance, has visible procedures and results allows the object to move slowly during the inspection procedure, does not need phase unwrapping, and has a quick image processing speed. As an application, this NDT technique is used to detect defects in composite materials and the resulting deformation phase gradient image shows a better visual effect than normal ESPI.

  14. Fault determinations in electroexplosive devices by nondestructive techniques

    NASA Technical Reports Server (NTRS)

    Menichelli, V. J.; Rosenthal, L. A.

    1972-01-01

    Several nondestructive test techniques were developed for electroexplosive devices. The bridgewire responds, when pulsed with a safe level current, by generating a characteristic heating curve. The response is indicative of the electrothermal behavior of the bridgewire-explosive interface. Bridgewires which deviate from the characteristic heating curve were dissected and examined to determine the cause of the abnormality. Deliberate faults were fabricated into squibs. The relationship of the specific abnormality and the fault associated with it is demonstrated.

  15. Nondestructive evaluation technique using infrared thermography and terahertz imaging

    NASA Astrophysics Data System (ADS)

    Sakagami, Takahide; Shiozawa, Daiki; Tamaki, Yoshitaka; Iwama, Tatsuya

    2016-05-01

    Nondestructive testing (NDT) techniques using pulse heating infrared thermography and terahertz (THz) imaging were developed for detecting deterioration of oil tank floor, such as blister and delamination of corrosion protection coating, or corrosion of the bottom steel plate under coating. Experimental studies were conducted to demonstrate the practicability of developed techniques. It was found that the pulse heating infrared thermography was utilized for effective screening inspection and THz-TDS imaging technique performed well for the detailed inspection of coating deterioration and steel corrosion.

  16. Determining plutonium in spent fuel with nondestructive assay techniques

    SciTech Connect

    Tobin, Stephen J; Charlton, William S; Fensin, Michael L; Menlove, Howard O; Hoover, A S; Quiter, B J; Rajasingam, A; Swinhoe, M T; Thompson, S J; Charlton, W S; Ehinger, M H; Sandoval, N P; Saavedra, S F; Strohmeyer, D

    2009-01-01

    There are a variety of motivations for quantifying plutonium in used (spent) fuel assemblies by means of nondestructive assay including the following: shipper/receiver difference, input accountability at reprocessing facilities and burnup credit at repositories or fuel storage facilities. Twelve NDA techniques were identified that provide information about the composition of an assembly. Unfortunately, none of these techniques is capable of determining the Pu mass in an assembly on its own. However, it is expected that the Pu mass can be quantified by combining a few of the techniques. Determining which techniques to combine and estimating the expected performance of such a system is the purpose of the research effort recently begun. The research presented here is a complimentarily experimental effort. This paper will focus on experimental results of one of the twelve non-destructive assay techniques - passive neutron albedo reactivity. The passive neutron albedo reactivity techniques work by changing the multiplication the pin experiences between two separate measurements. Since a single spent fuel pin has very little multiplication, this is a challenging measurement situation for the technique. Singles and Doubles neutron count rate were measured at Oak Ridge National Laboratory for three different burnup pins to test the capability of the passive neutron albedo reactivity technique.

  17. Application of Nondestructive Testing Techniques to Materials Testing.

    DTIC Science & Technology

    1986-02-01

    7D-Al?2 605 APPLICATION OF NONDESTRUCTIVE TESTING TECHNIQUES To / MATERIALS TESTING(U) STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS G S KIND FEB...U EDWARD L. GINTZON LAB, W.W. HANSEN LAB OF PHYSIC ! 2306/A2 (%J STANFORD CA 94305’ 11 ,. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE Feb 1986...we could improve optical systems by employing modern electronic techniques within the optical system. Our purpose has been to make accurate profile

  18. Development of Nondestructive Measuring Technique of Environmental Radioactive Strontium

    NASA Astrophysics Data System (ADS)

    Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Yoshida, Tatsuru; Murata, Jiro

    The Fukushima first nuclear power plant accident was triggered by the Japanese big earthquake in 2011. The main radioactivity concerned after the accident are I-131 (half-life 8.0 days), Cs-134 (2.1 years) and 137 (30 years), Sr-89 (51 days) and 90 (29 years). We are aiming to establish a new detection technique which enables us to realize quantitative evaluation of the strontium radioactivity by means of nondestructive measurement without chemical separation processing, which is concerned to be included inside foods, environmental water and soil around us, in order to prevent us from undesired internal exposure to the radiation.

  19. Nondestructive Evaluation of Thick Concrete Using Advanced Signal Processing Techniques

    SciTech Connect

    Clayton, Dwight A; Barker, Alan M; Santos-Villalobos, Hector J; Albright, Austin P; Hoegh, Kyle; Khazanovich, Lev

    2015-09-01

    The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years [1]. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the various nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations.

  20. Theory and experimental technique for nondestructive evaluation of ceramic composites

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1990-01-01

    The important ultrasonic scattering mechanisms for SiC and Si3N4 ceramic composites were identified by examining the interaction of ultrasound with individual fibers, pores, and grains. The dominant scattering mechanisms were identified as asymmetric refractive scattering due to porosity gradients in the matrix material, and symmetric diffractive scattering at the fiber-to-matrix interface and at individual pores. The effect of the ultrasonic reflection coefficient and surface roughness in the ultrasonic evaluation was highlighted. A new nonintrusive ultrasonic evaluation technique, angular power spectrum scanning (APSS), was presented that is sensitive to microstructural variations in composites. Preliminary results indicate that APSS will yield information on the composite microstructure that is not available by any other nondestructive technique.

  1. Ultrasonic techniques for nondestructive testing of standing trees.

    PubMed

    Bucur, V

    2005-02-01

    The aim of this study is to assess wood quality of standing trees with ultrasonic velocity methods. The ultrasonic techniques currently used are: scattering based techniques that use travel time and other wave parameters for measuring the elastic constants of wood, and ultrasonic tomographic imaging techniques which seek to provide a high resolution picture of the defect. Scattering based techniques were firstly used as nondestructive techniques with increment cores of 5 mm diameter. On these specimens measurements with bulk waves--longitudinal and shear were used to detect the influence of sylvicultural treatment (pruning) on wood quality and also to detect defects (slope of grain, wavy figures). High resolution imaging techniques were developed for imaging abnormalities induced by biological attacks of fungi or insects in standing trees. In this case, ultrasonic tomography refers to cross-sectional imaging of trees from data collected by illuminating the tree from different directions. Ultrasonic images were reconstructed from the time of flight. The images were reconstructed from 120 measurements in situ and through the bark with direct transmission technique, using 1 MHz transducers. The resolution is 5 cm.

  2. Non-destructive evaluation of anchorage zones by ultrasonics techniques.

    PubMed

    Kharrat, M; Gaillet, L

    2015-08-01

    This work aims to evaluate the efficiency and reliability of two Non-Destructive Testing (NDT) methods for damage assessment in bridges' anchorages. The Acousto-Ultrasonic (AU) technique is compared to classical Ultrasonic Testing (UT) in terms of defect detection and structural health classification. The AU technique is firstly used on single seven-wire strands damaged by artificial defects. The effect of growing defects on the waves traveling through the strands is evaluated. Thereafter, three specimens of anchorages with unknown defects are inspected by the AU and UT techniques. Damage assessment results from both techniques are then compared. The structural health conditions of the specimens can be then classified by a damage severity criterion. Finally, a damaged anchorage socket with mastered defects is controlled by the same techniques. The UT allows the detection and localization of damaged wires. The AU technique is used to bring out the effect of defects on acoustic features by comparing a healthy and damaged anchorage sockets. It is concluded that the UT method is suitable for local and crack-like defects, whereas the AU technique enables the assessment of the global structural health of the anchorage zones.

  3. Research in nondestructive evaluation techniques for nuclear reactor concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight; Smith, Cyrus

    2014-02-01

    The purpose of the Materials Aging and Degradation (MAaD) Pathway of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program is to develop the scientific basis for understanding and predicting longterm environmental degradation behavior of material in nuclear power plants and to provide data and methods to assess the performance of systems, structures, and components (SSCs) essential to safe and sustained nuclear power plant operations. The understanding of aging-related phenomena and their impacts on SSCs is expected to be a significant issue for any nuclear power plant planning for long-term operations (i.e. service beyond the initial license renewal period). Management of those phenomena and their impacts during long-term operations can be better enable by improved methods and techniques for detection, monitoring, and prediction of SSC degradation. The MAaD Pathway R&D Roadmap for Concrete, "Light Water Reactor Sustainability Nondestructive Evaluation for Concrete Research and Development Roadmap", focused initial research efforts on understanding the recent concrete issues at nuclear power plants and identifying the availability of concrete samples for NDE techniques evaluation and testing. [1] An overview of the research performed by ORNL in these two areas is presented here.

  4. Nondestructive NMR technique for moisture determination in radioactive materials.

    SciTech Connect

    Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L.; Kaminski, M.

    1998-12-04

    This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ({sup 3}H, {sup 3}He, {sup 239}Pu, {sup 241}Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO{sub 2} and UO{sub 2} systems. The total moisture was quantified by means of {sup 1}H NMR detection of H{sub 2}O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96.

  5. Low-frequency electromagnetic technique for nondestructive evaluation

    NASA Astrophysics Data System (ADS)

    Dalichaouch, Yacine; Singsaas, Alan L.; Putris, Firas; Perry, Alexander R.; Czipott, Peter V.

    2000-05-01

    We have developed a low frequency electromagnetic technique using sensitive room temperature magnetoresistive (MR) sensors for a variety of nondestructive evaluation (NDE) applications. These applications include the NDE of medical implants and aircraft structures, the detection of cracks and corrosion in metals, the detection of ferromagnetic foreign objects in the eye and the brain, and the noninvasive determination of iron content in the liver. Our technique consists of applying a low frequency ac magnetic field to the sample and detecting the sample response. The low excitation frequency enables us to probe deep into metal structures; the sensitivity of the MR sensor allows us to detect weak responses from the sample without applying too large an excitation field, particularly in the case of human tissue. The MR sensors are small and relatively inexpensive compared to other sensitive magnetic field sensors such as fluxgates and superconducting quantum interference devices or SQUIDs; hence the resulting NDE instrument will be compact and cost-efficient, enabling its commercialization for practical applications. In this paper, we focus primarily on NDE of orthopedic implants.

  6. Research in nondestructive evaluation techniques for nuclear reactor concrete structures

    SciTech Connect

    Clayton, Dwight; Smith, Cyrus

    2014-02-18

    The purpose of the Materials Aging and Degradation (MAaD) Pathway of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program is to develop the scientific basis for understanding and predicting longterm environmental degradation behavior of material in nuclear power plants and to provide data and methods to assess the performance of systems, structures, and components (SSCs) essential to safe and sustained nuclear power plant operations. The understanding of aging-related phenomena and their impacts on SSCs is expected to be a significant issue for any nuclear power plant planning for long-term operations (i.e. service beyond the initial license renewal period). Management of those phenomena and their impacts during long-term operations can be better enable by improved methods and techniques for detection, monitoring, and prediction of SSC degradation. The MAaD Pathway R and D Roadmap for Concrete, 'Light Water Reactor Sustainability Nondestructive Evaluation for Concrete Research and Development Roadmap', focused initial research efforts on understanding the recent concrete issues at nuclear power plants and identifying the availability of concrete samples for NDE techniques evaluation and testing. [1] An overview of the research performed by ORNL in these two areas is presented here.

  7. Nondestructive analysis of oil shales with PGNAA technique

    SciTech Connect

    Maly, J.; Bozorgmanesh, H.

    1984-02-01

    The feasibility of nondestructive analysis of oil shales using the prompt gamma neutron activation analysis (PGNAA) technique was studied. The PGNAA technique, developed originally for continuous analysis of coal on the belt, was applied to the analysis of eight oil-shale samples, containing between 9 and 60 gallons of oil per ton and 0.8% to 3.4% hydrogen. The PGNAA technique was modified using four neutron moderation conditions: non-moderated neutrons; non-moderated and partially moderated neutrons reflected from a water box behind the source; neutrons moderated in a water box behind and in front of the source; and neutrons strongly moderated in a polyethylene block placed in front of the source and with reflected neutrons from a water box behind the source. The studied oil shales were measured in their aluminum or wooden (masonite) boxes. The obtained Ge-Li spectra were processed by LSI-11/23 computer, using the modified programs previously developed by SAI for continuous coal analysis. The results of such processing (the peak areas for several gamma lines) were corrected and plotted against the weight percent of each analyzed element (from the chemical analysis). Response curves developed for H, C, N, S, Na, Mg, Al, Si, Ti, Ca, Fe and K show generally good linear proportions of peak area to the weight percent of the element. For hydrogen determination, NMD conditions had to be used where the response curve was not linear, but followed a curve whose slope rose with hydrogen concentration. This effect is caused by improving neutron self-moderation in sample boxes of rich oil shales, as compared to poor self-moderation of neutrons in very lean oil shales. The moisture in oil shales was measured by microwave absorption technique in small masonite boxes. This method was calibrated four times using oil-shale samples mixed gradually with larger and larger amounts of water.

  8. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-6, Radiography Inspection.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This sixth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I explains radiographic inspection as a means of nondestructively examining components, assemblies, structures, and fabricated piping. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  9. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-6, Radiography Inspection.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This sixth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I explains radiographic inspection as a means of nondestructively examining components, assemblies, structures, and fabricated piping. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  10. Corrosion Evaluation of Carbon Steels Using Nondestructive Technique

    NASA Astrophysics Data System (ADS)

    Lee, Jin Kyung; Lee, Sang Pill; Lee, Moon Hee; Lee, Joon Hyun; Park, Jun Young

    Primary water stress corrosion crack (PWSCC) in the piping used at the nuclear power plant has been one of the major issues for the safety of plant. The major objective in this paper is to clarify the corrosion degree and damage by the PWSCC using nondestructive technique. The instrument of the tube typed reactor with the internal conditions of the temperature of 473K under pressure of 10 MPa was designed for corrosion of the material. The tensile specimens of the same material with the reactor were corroded in the reactor for evaluation of mechanical properties according to the corrosion. The corrosion of the specimen was maintained over one year, and an acoustic emission technique was applied to inspect the corrosion damage of the specimen periodically. A tensile test was performed for the corroded specimen, and then the elastic waves caused the deformation of the corroded specimen were analyzed. With the increase of the corrosion time the elastic waves generated in the specimen due to the tensile load showed a little difference, and these differences of the waves work as a cause of the change of acoustic emission (AE) parameters. The number of AE events at the beginning of the load increased with the corrosion time. AE parameters of amplitude and energy decreased as the corrosion times increased, while the level of duration time and count were increased with the corrosion periods. The velocity and attenuation of the elastic wave were also analyzed for the specimen, and these factors showed a close relation with the corrosion times. In addition, SEM and XRD analysis were performed to evaluate the damage behavior of the carbon steel due to corrosion.

  11. Conceptual Ideas for New Nondestructive UF6 Cylinder Assay Techniques

    SciTech Connect

    Miller, Karen A.

    2012-05-02

    Nondestructive assay (NDA) measurements of uranium cylinders play an important role in helping the International Atomic Energy Agency (IAEA) safeguard uranium enrichment plants. Traditionally, these measurements have consisted of a scale or load cell to determine the mass of UF{sub 6} in the cylinder combined with a gamma-ray measurement of the 186 keV peak from {sup 235}U to determine enrichment. More recently, Los Alamos National Laboratory (LANL) and Pacific Northwest National Laboratory (PNNL) have developed systems that exploit the passive neutron signal from UF{sub 6} to determine uranium mass and/or enrichment. These include the Uranium Cylinder Assay System (UCAS), the Passive Neutron Enrichment Meter (PNEM), and the Hybrid Enrichment Verification Array (HEVA). The purpose of this report is to provide the IAEA with new ideas on technologies that may or may not be under active development but could be useful for UF{sub 6} cylinder assay. To begin, we have included two feasibility studies of active interrogation techniques. There is a long history of active interrogation in the field of nuclear safeguards, especially for uranium assay. Both of the active techniques provide a direct measure of {sup 235}U content. The first is an active neutron method based on the existing PNEM design that uses a correlated {sup 252}Cf interrogation source. This technique shows great promise for UF{sub 6} cylinder assay and is based on advanced technology that could be implemented in the field in the near term. The second active technique is nuclear resonance fluorescence (NRF). In the NRF technique, a bremsstrahlung photon beam could be used to illuminate the cylinder, and high-resolution gamma-ray detectors would detect the characteristic de-excitation photons. The results of the feasibility study show that under certain measurement geometries, NRF is impractical for UF6 cylinder assay, but the 'grazing transmission' and 'secant transmission' geometries have more potential

  12. A non-destructive DNA sampling technique for herbarium specimens.

    PubMed

    Shepherd, Lara D

    2017-01-01

    Herbarium specimens are an important source of DNA for plant research but current sampling methods require the removal of material for DNA extraction. This is undesirable for irreplaceable specimens such as rare species or type material. Here I present the first non-destructive sampling method for extracting DNA from herbarium specimens. DNA was successfully retrieved from robust leaves and/or stems of herbarium specimens up to 73 years old.

  13. Nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Mandel, G.; Carpenter, J. L., Jr.; Stuarke, W. F.

    1977-01-01

    Technological survey summarizes accumulated knowledge of nondestructive-evaluation (NDE) testing methodology application and reliability as it is presented in literature covering time period from 1962 to 1975.

  14. Testing methods and techniques: Quality control and nondestructive testing: A complication

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A variety of devices and techniques useful in nondestructive testing is described. Ranging in complexity from an automated ultrasonic testing system designed for complex laminated honeycomb structures, to a flexible leak detector probe, the items represent either potential savings in cost and time, or improvement in inspection quality over past techniques. Data cover weld and braze inspection, leak detection, and inspection of composite materials.

  15. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-2, Leak Tests.

    ERIC Educational Resources Information Center

    Groseclose, Richard

    This second in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes the predominantly used leak test methods in nuclear power plants. More specifically, the module describes these test methods, the testing techniques, and the associated quality assurance requirements. The module follows a typical…

  16. Nondestructive evaluation techniques for nickel-cadmium aerospace battery cells

    NASA Technical Reports Server (NTRS)

    Haak, R.; Tench, D.

    1982-01-01

    The ac impedance characteristics of Ni-Cd cells as an in-situ, nondestructive means of determining cell lifetime, particularly with respect to the probability of premature failure were evaluated. Emphasis was on evaluating Ni-Cd cell impedance over a wide frequency range (10,000 to 0.0004 Hz) as the cells were subjected to charge/discharge cycle testing. The results indicate that cell degradation is reflected in the low frequency (Warburg) impedance characteristics associated with diffusion processes. The Warburg slope (W) was found to steadily increase as a function of cell aging for completely discharged cells. In addition, based on data for two cells, a high or rapidly increasing value for W signals imminent cell failure by one mechanism. Degradation by another mechanism is apparently reflected in a fall-off (roll-over) of W at lower frequencies. As a secondary result, the frequency dependence of the absolute cell impedance at low frequencies (5 - 500 mHz) was found to be a good indication of the cell state-of-charge.

  17. Nondestructive evaluation: A survey of NASA contributions, chapter 1, Chapter 11, cover page, acknowledgements, and contents

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A survey of nondestructive evaluation (NDE) technology, which is discussed in terms of popular demands for a greater degree of quality, reliability, and safety in industrial products, is presented as an overview of the NDE field to serve the needs of middle management. Three NDE methods are presented: acoustic emission, the use of coherent (laser)light, and ultrasonic holography.

  18. Nondestructive techniques for assaying fuel debris in piping at Three Mile Island Unit 2

    SciTech Connect

    Vinjamuri, K.; McIsaac, C.V.; Beller, L.S.; Isaacson, L.; Mandler, J.W.; Hobbins, R.R. Jr.

    1981-11-01

    Four major categories of nondestructive techniques - ultrasonic, passive gamma ray, infrared detection, and remote video examination - have been determined to be feasible for assaying fuel debris in the primary coolant system of the Three Mile Island Unit 2 (TMI-2) Reactor. Passive gamma ray detection is the most suitable technique for the TMI-2 piping; however, further development of this technique is needed for specific application to TMI-2.

  19. Application of nondestructive gamma-ray and neutron techniques for the safeguarding of irradiated fuel materials

    SciTech Connect

    Phillips, J.R.; Halbig, J.K.; Lee, D.M.; Beach, S.E.; Bement, T.R.; Dermendjiev, E.; Hatcher, C.R.; Kaieda, K.; Medina, E.G.

    1980-05-01

    Nondestructive gamma-ray and neutron techniques were used to characterize the irradiation exposures of irradiated fuel assemblies. Techniques for the rapid measurement of the axial-activity profiles of fuel assemblies have been developed using ion chambers and Be(..gamma..,n) detectors. Detailed measurements using high-resolution gamma-ray spectrometry and passive neutron techniques were correlated with operator-declared values of cooling times and burnup.

  20. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-3, Hydrostatic Tests.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This third in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes the principles and practices associated with hydrostatic testing. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student,…

  1. Nondestructive Inspection Techniques for Friction Stir Weld Verification on the Space Shuttle External Tank

    NASA Technical Reports Server (NTRS)

    Suits, Michael W.; Leak, Jeffery; Bryson, Craig

    2003-01-01

    Friction Stir Welding (FSW) has gained wide acceptance as a reliable joining process for aerospace hardware as witnessed by its recent incorporation into the Delta Launch vehicle cryotanks. This paper describes the development of nondestructive evaluation methods and techniques used to verify the FSW process for NASA's Space Shuttle.

  2. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-3, Hydrostatic Tests.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This third in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes the principles and practices associated with hydrostatic testing. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student,…

  3. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-5, Fundamentals of Radiography.

    ERIC Educational Resources Information Center

    Groseclose, Richard

    This fifth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I explains the radiographic process, from radiation source selection to equipment and specimen selection and arrangement, and film processing. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  4. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-4, Liquid Penetrant Tests.

    ERIC Educational Resources Information Center

    Espy, John

    This fourth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes liquid penetrant examination which provides an effective method of detecting undesired, invisible surface discontinuities. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  5. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-1, Visual Tests.

    ERIC Educational Resources Information Center

    Wasil, Ed

    This first in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes visual examination as an independent inspection activity. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5)…

  6. Nondestructive evaluation of green wood using stress wave and transverse vibration techniques

    Treesearch

    Udaya B. Halabe; Gangadhar M. Bidigalu; Hota V.S. GangaRao; Robert J. Ross

    1997-01-01

    Longitudinal stress wave and transverse vibration nondestructive testing (NDT) techniques have proven to be accurate means of evaluating the quality of wood based products. Researchers have found strong relationships between stress wave and transverse vibration parameters (e.g., wave velocity and modulus of elasticity predicted using NDT measurements) with the actual...

  7. Nondestructive spectroscopic and imaging techniques for quality evaluation and assessment of fish and fish products.

    PubMed

    He, Hong-Ju; Wu, Di; Sun, Da-Wen

    2015-01-01

    Nowadays, people have increasingly realized the importance of acquiring high quality and nutritional values of fish and fish products in their daily diet. Quality evaluation and assessment are always expected and conducted by using rapid and nondestructive methods in order to satisfy both producers and consumers. During the past two decades, spectroscopic and imaging techniques have been developed to nondestructively estimate and measure quality attributes of fish and fish products. Among these noninvasive methods, visible/near-infrared (VIS/NIR) spectroscopy, computer/machine vision, and hyperspectral imaging have been regarded as powerful and effective analytical tools for fish quality analysis and control. VIS/NIR spectroscopy has been widely applied to determine intrinsic quality characteristics of fish samples, such as moisture, protein, fat, and salt. Computer/machine vision on the other hand mainly focuses on the estimation of external features like color, weight, size, and surface defects. Recently, by incorporating both spectroscopy and imaging techniques in one system, hyperspectral imaging cannot only measure the contents of different quality attributes simultaneously, but also obtain the spatial distribution of such attributes when the quality of fish samples are evaluated and measured. This paper systematically reviews the research advances of these three nondestructive optical techniques in the application of fish quality evaluation and determination and discuss future trends in the developments of nondestructive technologies for further quality characterization in fish and fish products.

  8. Non-destructive techniques for determining the material characteristics of Cr-Mo-V rotor steel

    SciTech Connect

    Goto, Toru; Kadoya, Yoshikuni; Konishi, Takashi; Kamimura, Takeo; Suyama, Shouji; Haruki, Nirou; Ikuno, Takeshi; Yoshimura, Kouji

    1994-12-31

    Long-term service causes material deterioration, such as the accumulation of creep and fatigue damage, as well as softening and embrittlement, in the high-temperature components of fossil fuel power plants. Therefore, in order to extend plant life at minimum cost without any accidental outages, it is important to observe the material state, especially of rotors and conduct necessary repairs or replace them at the most appropriate time. Therefore, there is a need for non-destructive techniques to evaluate the material characteristics of Cr-Mo-V rotors under service. In this paper, a comparative report of non-destructive techniques using artificially aged and crept Cr-Mo-V steel specimens is given. The techniques tested include replication, hardness measurement, electro-magnetic and ultrasonic techniques, and conventional metallurgical techniques, which have been here to fore usable only in the laboratory, but due to expected advances in the non-destructive sampling of material from service rotors these techniques are now usable in the field. As a result of the studies, the features of each technique are well recognized and the suggestions for the further development of NDE methods for the evaluation of creep damage in Cr-Mo-V rotors are presented.

  9. The application of non-destructive techniques to the testing of a wind turbine blade

    SciTech Connect

    Sutherland, H.; Beattie, A.; Hansche, B.; Musial, W.; Allread, J.; Johnson, J.; Summers, M.

    1994-06-01

    NonDestructive Testing (NDT), also called NonDestructive Evaluation (NDE), is commonly used to monitor structures before, during, and after testing. This paper reports on the use of two NDT techniques to monitor the behavior of a typical wind turbine blade during a quasi-static test-to-failure. The two NDT techniques used were acoustic emission and coherent optical. The former monitors the acoustic energy produced by the blade as it is loaded. The latter uses electron shearography to measure the differences in surface displacements between two load states. Typical results are presented to demonstrate the ability of these two techniques to locate and monitor both high damage regions and flaws in the blade structure. Furthermore, this experiment highlights the limitations in the techniques that must be addressed before one or both can be transferred, with a high probability of success, to the inspection and monitoring of turbine blades during the manufacturing process and under normal operating conditions.

  10. Destructive and Non-Destructive Analysis Techniques for Failure Detection of QFN Packages

    NASA Astrophysics Data System (ADS)

    Adhila, M. N.; Wedianti, S.; Suhaimi, W. S. W. M.; Aishah, I.

    2010-03-01

    One of the latest developments in packaging technology is the QFN (Quad Flat Non-Lead) packages, which is both a chip scale package and plastic encapsulated package with lead pad at the bottom. In this paper, different type of commercial QFN single die packages were characterized by using destructive and non-destructive techniques. Non-destructive techniques such as Scanning Acoustic Microscope (SAM) and X-Ray analysis were used to observe package cracking, delamination and other failure mode. Application of SAM include detection of delaminations between lead frame, die face, paddle, heat sink, cracks and plastic encapsulant. In comparison to other techniques, SAM is sensitive to detect beneath the surface of devices which would be inaccessible otherwise by both conventional optical and electron microscopy inspection methods. Destructive technique such as Field Emission Electron Microscopy (FESEM) was implemented to address the failures of the QFN single die packages such as die cracking, lifted ball bonds and other failure mode.

  11. Non-destructive evaluation techniques for chemical weapons destruction

    SciTech Connect

    Hartwell, J.K.; Caffrey, A.J.

    1996-09-01

    fThe safe and verifiable disposition, either by incineration or chemical neutralization of chemical warfare (CW) agents requires correct {ital a priori} identification of each munition or container to be processed. A variety of NDE techniques have been used or tested for the examination and characterization of munitions. In the U.S., three widely used techniques are X-ray radiography, acoustic resonance spectroscopy (ARS), and prompt gamma ray neutron activation analysis (PINS). The technical bases, instrumental implementations, and applications of the U.S. versions of these methods are briefly discussed. 10 refs., 2 figs., 1 tab.

  12. Infrared Contrast Analysis Technique for Flash Thermography Nondestructive Evaluation

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay

    2014-01-01

    The paper deals with the infrared flash thermography inspection to detect and analyze delamination-like anomalies in nonmetallic materials. It provides information on an IR Contrast technique that involves extracting normalized contrast verses time evolutions from the flash thermography infrared video data. The paper provides the analytical model used in the simulation of infrared image contrast. The contrast evolution simulation is achieved through calibration on measured contrast evolutions from many flat bottom holes in the subject material. The paper also provides formulas to calculate values of the thermal measurement features from the measured contrast evolution curve. Many thermal measurement features of the contrast evolution that relate to the anomaly characteristics are calculated. The measurement features and the contrast simulation are used to evaluate flash thermography inspection data in order to characterize the delamination-like anomalies. In addition, the contrast evolution prediction is matched to the measured anomaly contrast evolution to provide an assessment of the anomaly depth and width in terms of depth and diameter of the corresponding equivalent flat-bottom hole (EFBH) or equivalent uniform gap (EUG). The paper provides anomaly edge detection technique called the half-max technique which is also used to estimate width of an indication. The EFBH/EUG and half-max width estimations are used to assess anomaly size. The paper also provides some information on the "IR Contrast" software application, half-max technique and IR Contrast feature imaging application, which are based on models provided in this paper.

  13. Development of a nondestructive vibration technique for bond assessment of Space Shuttle tiles

    NASA Technical Reports Server (NTRS)

    Moslehy, Faissal A.

    1994-01-01

    This final report describes the achievements of the above titled project. The project is funded by NASA-KSC (Grant No. NAG 10-0117) for the period of 1 Jan. to 31 Dec. 1993. The purpose of this project was to develop a nondestructive, noncontact technique based on 'vibration signature' of tile systems to quantify the bond conditions of the thermal protection system) tiles of Space Shuttle orbiters. The technique uses a laser rapid scan system, modal measurements, and finite element modeling. Finite element models were developed for tiles bonded to both clamped and deformable integrated skin-stringer orbiter mid-fuselage. Results showed that the size and location of a disbonded tile can be determined from frequency and mode shape information. Moreover, a frequency response survey was used to quickly identify the disbonded tiles. The finite element results were compared with experimentally determined frequency responses of a 17-tile test panel, where a rapidscan laser system was employed. An excellent degree of correlation between the mathematical simulation and experimental results was realized. An inverse solution for single-tile assemblies was also derived and is being implemented into a computer program that can interact with the modal testing software. The output of the program displays the size and location of disbond. This program has been tested with simulated input (i.e., finite element data), and excellent agreement between predicted and simulated disbonds was shown. Finally, laser vibration imaging and acoustic emission techniques were shown to be well suited for detecting and monitoring the progressive damage in Graphite/Epoxy composite materials.

  14. Application of Nondestructive Testing Techniques to Materials Testing.

    DTIC Science & Technology

    1987-12-01

    phase . The ideas behind it are basic to much of the present work we are carrying out on new programs on phase contrast microscopy , and...of phase contrast microscopy are already familiar. In reflection mi- croscopy, measurement of phase makes it possible to measure profiles, or height...frequency shifting, and a novel "heterodyne phase contrast " technique using a time-variable electro-optic phase plate, somewhat similar to a Zernike

  15. Applications of Advanced Nondestructive Measurement Techniques to Address Safety of Flight Issues on NASA Spacecraft

    NASA Technical Reports Server (NTRS)

    Prosser, Bill

    2016-01-01

    Advanced nondestructive measurement techniques are critical for ensuring the reliability and safety of NASA spacecraft. Techniques such as infrared thermography, THz imaging, X-ray computed tomography and backscatter X-ray are used to detect indications of damage in spacecraft components and structures. Additionally, sensor and measurement systems are integrated into spacecraft to provide structural health monitoring to detect damaging events that occur during flight such as debris impacts during launch and assent or from micrometeoroid and orbital debris, or excessive loading due to anomalous flight conditions. A number of examples will be provided of how these nondestructive measurement techniques have been applied to resolve safety critical inspection concerns for the Space Shuttle, International Space Station (ISS), and a variety of launch vehicles and unmanned spacecraft.

  16. Promising quantitative nondestructive evaluation techniques for composite materials

    NASA Technical Reports Server (NTRS)

    Williams, J. H., Jr.; Lee, S. S.

    1985-01-01

    Some recent results in the area of the ultrasonic, acoustic emission, thermographic, and acousto-ultrasonic NDE of composites are reviewed. In particular, attention is given to the progress in the use of ultrasonic attenuation, acoustic emission (parameter) delay, liquid-crystal thermography, and the stress wave factor in structural integrity monitoring of composite materials. The importance of NDE flaw significance characterizations is emphasized since such characterizations can directly indicate the appropriate NDE technique sensitivity requirements. The role of the NDE of flawed composites with and without overt defects in establishing quantitative accept/reject criteria for structural integrity assessment is discussed.

  17. Comparative testing of nondestructive examination techniques for concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight A.; Smith, Cyrus M.

    2014-03-01

    A multitude of concrete-based structures are typically part of a light water reactor (LWR) plant to provide foundation, support, shielding, and containment functions. Concrete has been used in the construction of nuclear power plants (NPPs) because of three primary properties, its inexpensiveness, its structural strength, and its ability to shield radiation. Examples of concrete structures important to the safety of LWR plants include containment building, spent fuel pool, and cooling towers. Comparative testing of the various NDE concrete measurement techniques requires concrete samples with known material properties, voids, internal microstructure flaws, and reinforcement locations. These samples can be artificially created under laboratory conditions where the various properties can be controlled. Other than NPPs, there are not many applications where critical concrete structures are as thick and reinforced. Therefore, there are not many industries other than the nuclear power plant or power plant industry that are interested in performing NDE on thick and reinforced concrete structures. This leads to the lack of readily available samples of thick and heavily reinforced concrete for performing NDE evaluations, research, and training. The industry that typically performs the most NDE on concrete structures is the bridge and roadway industry. While bridge and roadway structures are thinner and less reinforced, they have a good base of NDE research to support their field NDE programs to detect, identify, and repair concrete failures. This paper will summarize the initial comparative testing of two concrete samples with an emphasis on how these techniques could perform on NPP concrete structures.

  18. Nondestructive characterization of prepreg ageing using nuclear magnetic resonance techniques

    SciTech Connect

    Koeller, E.; Dobmann, G.; Kuhn, W. )

    1990-01-01

    Initial results are presented on the application of NMR techniques to prepregs in order to characterize the crosslink state under exposure to room and elevated (50 C) temperature. The experiments were conducted with a MSL-400 Bruker NMR spectrometer and microimaging system which works at 400 MHz. Aside from the sensitive measurement of the cross-link density there is also the potential to separate the influence of moisture content as a further parameter contributing to the aging process. It is shown that these experimental results correlate with results of destructive tests and document the potential of NMR as a NDT tool. An NMR-image of the moisture distribution in a glassfiber reinforced expoxy resin sample is shown. 17 refs.

  19. Feasibility Study of Non-Destructive Techniques to Measure Corrosion in SAVY Containers

    SciTech Connect

    Davenport, Matthew Nicholas

    2016-07-15

    Stainless Steel SAVY containers are used to transport and store nuclear material. They are prone to interior corrosion in the presence of certain chemicals and a low-oxygen environment. SAVY containers also have relatively thin walls to reduce their weight, making their structural integrity more vulnerable to the effects of corrosion. A nondestructive evaluation system that finds and monitors corrosion within containers in use would improve safety conditions and preclude hazards. Non-destructive testing can determine whether oxidation or corrosion is occurring inside the SAVY containers, and there are a variety of non-destructive testing methods that may be viable. The feasibility study described will objectively decide which method best fits the requirements of the facility and the problem. To improve efficiency, the containers cannot be opened during the non-destructive examination. The chosen technique should also be user-friendly and relatively quick to apply. It must also meet facility requirements regarding wireless technology and maintenance. A feasibility study is an objective search for a new technology or product to solve a particular problem. First, the design, technical, and facility feasibility requirements are chosen and ranked in order of importance. Then each technology considered is given a score based upon a standard ranking system. The technology with the highest total score is deemed the best fit for a certain application.

  20. Nondestructive pavement evaluation technique using falling weight deflectometer

    SciTech Connect

    Al-Nageim, H.; Al-Hakim, B.; Lesley, L.

    1996-11-01

    An analytical method to predict the mechanical properties of a multi-layer pavement structure is presented. The development of the model is based on a modified back calculation model, using a finite circular plate resting on an elastic layered system. The deflection of the pavement under the dynamic action of the falling weight deflectometer (FWD) is taken as a function of the load action and the characteristic strength of the layers comprising the system including the friction between the individual layers. The responses of the pavement during the impact loading of the falling weight are measured and analyzed to predict the stress, strain and coefficient of friction between the layers making the system. The results revealed that the model which incorporates the interface of friction coefficient in the back-analysis technique allows for a more accurate calculation of the mechanical properties of the pavements and thus can be used as a quality control to assess the state of adhesion between the pavement layer system.

  1. Microwaving Blood as a Non-Destructive Technique for Haemoglobin Measurements on Microlitre Samples

    PubMed Central

    Basey-Fisher, Toby H.; Guerra, Nadia; Triulzi, Chiara; Gregory, Andrew; Hanham, Stephen M.; Stevens, Molly M.; Maier, Stefan A.; Klein, Norbert

    2016-01-01

    The non-destructive ex vivo determination of haemoglobin (Hgb) concentration offers the capability to conduct multiple red blood cell haematological measurements on a single sample, an advantage that current optical techniques are unable to offer. Here, a microwave method and device for the accurate and non-destructive determination of Hgb concentration in microlitre blood samples are described. Using broadband microwave spectroscopy, a relationship is established between the dielectric properties of murine blood and Hgb concentration that is utilized to create a technique for the determination of Hgb concentration. Subsequently, a microwave dielectric resonator-microfluidic system is implemented in the analysis of 52 murine samples with microlitre volumes and Hgb concentrations ranging from 0 to 17 g dL−1. Using the characterized relationship, independent and minimally invasive Hgb measurements are made on nine healthy mice as well as seven with mutations in the Adenomatous polyposis coli (APC) gene that leads to colorectal cancer and consequently anaemia. PMID:24002989

  2. Nondestructive evaluation of fatigue damage on low-alloy steel by magnetic technique

    SciTech Connect

    Hirasawa, T.; Komura, I.; Chujow, N.

    1994-12-31

    In the nuclear power plant, fatigue damage is one of the most significant degradation behavior which is expected that the structural components is received during long term operation. In order to estimate the plant life and to ensure the reliability of the plants, nondestructive detection and evaluation of fatigue damage of the components are a key technology. Magneto mechanical acoustic emission (MAE) method was applied to the evaluation of fatigue damage of reactor pressure vessel steel. Several MAE parameters which were obtained from the signal processing and waveform analysis on fatigue specimens, were measured and investigated as a function of cumulative fatigue damage factor. Consequently, these MAE parameters were compared to the results by X-ray diffraction technique, hardness testing and microstructural observation. The usefulness of MAE method as the nondestructive evaluation technique of fatigue damage was discussed.

  3. Evaluation of adhesively bonded composites by nondestructive techniques

    NASA Astrophysics Data System (ADS)

    Malinowski, Paweł H.; Ecault, Romain; Wandowski, Tomasz; Ostachowicz, Wiesław M.

    2017-04-01

    Composite materials are commonly used in many branches of industry. One method to join or repair CFRP parts is by the use adhesive bonding. There is a search of effective methods for pre-bond assessment of bonded parts and post-bond inspection. Research reported here focuses on post-bond inspection of bonded CFRP plates. In this paper we reported results of two methods. We used noncontact ultrasonic testing (UT) technique as reference method. Ultrasonic testing was made in an immersion tank using phased-array probes. The second method was the electromechanical impedance (EMI). A piezoelectric sensors were surface mounted on each of the samples. Due to piezoelectric effect the electrical response of the sensor is related to mechanical response of the structure to which the sensors is bonded to. Measurements were conducted using HIOKI Impedance Analyzer IM3570. In order to perform a detailed study three samples of each kind were tested. There were three reference samples. The samples with modified adhesive bonds had three levels of severity, so there were three samples with each level of modification. The ultrasonic testing was focused on C-scan analysis taking into consideration the amplitude and time of flight (TOF). Two probes were used, one with 5 MHz frequency, second with 10 MHz. The EMI spectra were gathered up to 5 MHz and they were processed with signal processing algorithms in order to extract differences between reference samples and samples with modified bonds. The UT results provided relevant information about the investigated samples, while the EMI showed sensitivity to the level of adhesive bond modification.

  4. Nondestructive evaluation

    SciTech Connect

    Martz, H.E.

    1997-02-01

    Research reported in the thrust area of nondestructive evaluation includes: advanced 3-D imaging technologies; new techniques in laser ultrasonic testing; infrared computed tomography for thermal NDE of materials, structures, sources, and processes; automated defect detection for large laser optics; multistatic micropower impulse radar imaging for nondestructive evaluation; and multi-modal NDE for AVLIS pod shielding components.

  5. Evaluation of Mechanical Properties of Nuclear Materials Using Non-Destructive Ball Indentation Technique

    SciTech Connect

    Mathew, M.D.; Linga Murty, K.

    2002-07-01

    Integrity of structural components depends on the deformation and fracture behavior of materials. For evaluating the material condition in-service, it is generally not feasible or practical or advisable to cut samples from operating structures. Non-destructive testing (NDT) techniques are required to evaluate the mechanical properties. Although several NDT techniques such as ultrasound, magnetic strength, Barkhausen noise, microhardness etc., are employed for estimating the mechanical property degradation, these methodologies are generally empirical and indirect. Automated Ball Indentation (ABI) is a non-destructive testing technique for direct measurement of mechanical and fracture properties of metallic engineering materials. Because of the small area over which the test is carried out, it is possible to determine point to point variations in the mechanical and fracture properties, such as those that exist in weldments. Although ABI technique is non-intrusive, it is a state-of-the-art mechanical test that measures directly the current/local deformation behavior of the material. In this paper, we present results from studies on the application of ABI technique to determine tensile and fracture properties of ferritic steels, an austenitic stainless steel, a nickel base superalloy and Zircaloy in different thermo-mechanical conditions. The effects of aging and cold work on these properties were determined from the ABI tests. Gradients in mechanical properties of ferritic steel welds, particularly in the narrow heat-affected zone, were clearly established. ABI technique was found to be useful in determining the anisotropy in the tensile properties of Zircaloy cladding tubes. The technique has potential as a non-destructive method for assessing structural integrity of aged components. (authors)

  6. A study of the stress wave factor technique for nondestructive evaluation of composite materials

    NASA Technical Reports Server (NTRS)

    Sarrafzadeh-Khoee, A.; Kiernan, M. T.; Duke, J. C., Jr.; Henneke, E. G., II

    1986-01-01

    The acousto-ultrasonic method of nondestructive evaluation is an extremely sensitive means of assessing material response. Efforts continue to complete the understanding of this method. In order to achieve the full sensitivity of the technique, extreme care must be taken in its performance. This report provides an update of the efforts to advance the understanding of this method and to increase its application to the nondestructive evaluation of composite materials. Included are descriptions of a novel optical system that is capable of measuring in-plane and out-of-plane displacements, an IBM PC-based data acquisition system, an extensive data analysis software package, the azimuthal variation of acousto-ultrasonic behavior in graphite/epoxy laminates, and preliminary examination of processing variation in graphite-aluminum tubes.

  7. Nondestructive techniques for characterizing mechanical properties of structural materials: An overview

    NASA Technical Reports Server (NTRS)

    Vary, A.; Klima, S. J.

    1985-01-01

    An overview of nondestructive evaluation (NDE) is presented to indicate the availability and application potentials of techniques for quantitative characterization of the mechanical properties of structural materials. The purpose is to review NDE techniques that go beyond the usual emphasis on flaw detection and characterization. Discussed are current and emerging NDE techniques that can verify and monitor entrinsic properties (e.g., tensile, shear, and yield strengths; fracture toughness, hardness, ductility; elastic moduli) and underlying microstructural and morphological factors. Most of the techniques described are, at present, neither widely applied nor widely accepted in commerce and industry because they are still emerging from the laboratory. The limitations of the techniques may be overcome by advances in applications research and instrumentation technology and perhaps by accommodations for their use in the design of structural parts.

  8. Prompt Gamma Activation Analysis (PGAA): Technique of choice for nondestructive bulk analysis of returned comet samples

    NASA Technical Reports Server (NTRS)

    Lindstrom, David J.; Lindstrom, Richard M.

    1989-01-01

    Prompt gamma activation analysis (PGAA) is a well-developed analytical technique. The technique involves irradiation of samples in an external neutron beam from a nuclear reactor, with simultaneous counting of gamma rays produced in the sample by neutron capture. Capture of neutrons leads to excited nuclei which decay immediately with the emission of energetic gamma rays to the ground state. PGAA has several advantages over other techniques for the analysis of cometary materials: (1) It is nondestructive; (2) It can be used to determine abundances of a wide variety of elements, including most major and minor elements (Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni), volatiles (H, C, N, F, Cl, S), and some trace elements (those with high neutron capture cross sections, including B, Cd, Nd, Sm, and Gd); and (3) It is a true bulk analysis technique. Recent developments should improve the technique's sensitivity and accuracy considerably.

  9. Nondestructive techniques for characterizing mechanical properties of structural materials - An overview

    NASA Technical Reports Server (NTRS)

    Vary, A.; Klima, S. J.

    1986-01-01

    An overview of nondestructive evaluation (NDE) is presented to indicate the availability and application potentials of techniques for quantitative characterization of the mechanical properties of structural materials. The purpose is to review NDE techniques that go beyond the usual emphasis on flow detection and characterization. Discussed are current and emerging NDE techniques that can verify and monitor entrinsic properties (e.g., tensile, shear, and yield strengths; fracture toughness, hardness, ductility; elastic moduli) and underlying microstructural and morphological factors. Most of the techniques described are, at present, neither widely applied nor widely accepted in commerce and industry because they are still emerging from the laboratory. The limitations of the techniques may be overcome by advances in applications research and instrumentation technology and perhaps by accommodations for their use in the design of structural parts.

  10. Nondestructive evaluation of fatigue damage on low alloy steel by magnetomechanical acoustic emission technique

    SciTech Connect

    Hiraasawa, T.; Saito, K.; Komura, I.

    1995-08-01

    A modified magnetomechanical acoustic emission (MAE) technique, denoted Pulse-MAE, in which the magnetization by current pulse was adopted, was newly developed and its applicability was assessed for the nondestructive detection and evaluation of fatigue damage in reactor pressure vessel steel SFVV2 and SA508 class2. MAE signals were measured with both conventional MAE and Pulse-MAE technique for fatigue damaged specimens having several damage fractions, and peak voltage ratio Vp/Vo, where Vp and Vo were the peak voltage for damaged and undamaged specimen respectively, was chosen as a measure. Vp/Vo was found to increase monotonously at the early stage of fatigue process and the rate of increase in Vp/Vo during the fatigue process was larger in Pulse-MAE than conventional MAE. Therefore, Pulse-MAE technique proved to have higher sensitivity for the detection of fatigue damage compared with the conventional MAE and to have the potential of a practical technique for nondestructive detection and evaluation of fatigue damage in actual components.

  11. New International Program to Asses the Reliability of Emerging Nondestructive Techniques (PARENT)

    SciTech Connect

    Prokofiev, Iouri; Cumblidge, Stephen E.; Csontos, Aladar A.; Braatz, Brett G.; Doctor, Steven R.

    2013-01-25

    The Nuclear Regulatory Commission (NRC) established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) to follow on from the successful Program for the Inspection of Nickel alloy Components (PINC). The goal of the PARENT is to conduct a confirmatory assessment of the reliability of nondestructive evaluation (NDE) techniques for detecting and sizing primary water stress corrosion cracks (PWSCC) and applying the lessons learned from PINC to a series of round-robin tests. These open and blind round-robin tests will comprise a new set of typical pressure boundary components including dissimilar metal welds (DMWs) and bottom-mounted instrumentation penetrations. Open round-robin tests will engage research and industry teams worldwide to investigate and demonstrate the reliability of emerging NDE techniques to detect and size flaws with a wide range of lengths, depths, orientations, and locations. Blind round-robin tests will utilize various testing organizations, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from relatively easy to very difficult for detection and sizing. Blind and open round-robin testing started in late 2011 and early 2012, respectively. This paper will present the work scope with reports on progress, NDE methods evaluated, and project timeline for PARENT.

  12. Evaluation of nondestructive testing techniques for the space shuttle nonmetallic thermal protection system

    NASA Technical Reports Server (NTRS)

    Tiede, D. A.

    1972-01-01

    A program was conducted to evaluate nondestructive analysis techniques for the detection of defects in rigidized surface insulation (a candidate material for the Space Shuttle thermal protection system). Uncoated, coated, and coated and bonded samples with internal defects (voids, cracks, delaminations, density variations, and moisture content), coating defects (holes, cracks, thickness variations, and loss of adhesion), and bondline defects (voids and unbonds) were inspected by X-ray radiography, acoustic, microwave, high-frequency ultrasonic, beta backscatter, thermal, holographic, and visual techniques. The detectability of each type of defect was determined for each technique (when applicable). A possible relationship between microwave reflection measurements (or X-ray-radiography density measurements) and the tensile strength was established. A possible approach for in-process inspection using a combination of X-ray radiography, acoustic, microwave, and holographic techniques was recommended.

  13. Application of internal friction damping as a nondestructive evaluation technique for wire rope

    SciTech Connect

    Hochrein, A.A.; Sherrard, J.R.; Thiruvengadam, A.P.

    1983-05-01

    This paper discusses the technical feasibility of applying internal friction damping (IFD) as a nondestructive evaluation (NDE) technique to wire rope. The paper addresses the technical feasibility, laboratory testing on wire rope, and the associated test results on various samples of wire rope. These tests were evaluated in a series of laboratory experiments by measuring the internal friction damping during which several test parameters were changed. The test parameters including the tensile load, frequency of test load, exposure time of rope to load and variations in rope construction are discussed from the standpoint of IFD-NDE measurements.

  14. A systems approach of the nondestructive evaluation techniques applied to Scout solid rocket motors.

    NASA Technical Reports Server (NTRS)

    Oaks, A. E.

    1971-01-01

    Review and appraisal of the status of the nondestructive tests applied to Scout solid-propellant rocket motors, using analytical techniques to evaluate radiography for detecting internal discontinuities such as voids and unbonds. Information relating to selecting, performing, controlling, and evaluating the results of NDE tests was reduced to a common simplified format. With these data and the results of the analytical studies performed, it was possible to make the basic appraisals of the ability of a test to meet all pertinent acceptance criteria and, where necessary, provide suggestions to improve the situation.

  15. Development of nondestructive non-contact acousto-thermal evaluation technique for damage detection in materials

    NASA Astrophysics Data System (ADS)

    Sathish, Shamachary; Welter, John T.; Jata, Kumar V.; Schehl, Norman; Boehnlein, Thomas

    2012-09-01

    This paper presents the development of a new non-contact acousto-thermal signature (NCATS) nondestructive evaluation technique. The physical basis of the method is the measurement of the efficiency of the material to convert acoustic energy into heat, and a theoretical model has been used to evaluate this. The increase in temperature due to conversion of acoustic energy injected into the material without direct contact was found to depend on the thermal and elastic properties of the material. In addition, it depends on the experimental parameters of the acoustic source power, the distance between sample and acoustic source, and the period of acoustic excitation. Systematic experimental approaches to optimize each of the experimental variables to maximize the observed temperature changes are described. The potential of the NCATS technique to detect microstructural-level changes in materials is demonstrated by evaluating accumulated damage due to plasticity in Ti-6Al-4V and low level thermal damage in polymer matrix composites. The ability of the technique for macroscopic applications in nondestructive evaluation is demonstrated by imaging a crack in an aluminum test sample.

  16. Using the technique of computed tomography for nondestructive analysis of pharmaceutical dosage forms

    NASA Astrophysics Data System (ADS)

    de Oliveira, José Martins, Jr.; Mangini, F. Salvador; Carvalho Vila, Marta Maria Duarte; ViníciusChaud, Marco

    2013-05-01

    This work presents an alternative and non-conventional technique for evaluatingof physic-chemical properties of pharmaceutical dosage forms, i.e. we used computed tomography (CT) technique as a nondestructive technique to visualize internal structures of pharmaceuticals dosage forms and to conduct static and dynamical studies. The studies were conducted involving static and dynamic situations through the use of tomographic images, generated by the scanner at University of Sorocaba - Uniso. We have shown that through the use of tomographic images it is possible to conduct studies of porosity, densities, analysis of morphological parameters and performing studies of dissolution. Our results are in agreement with the literature, showing that CT is a powerful tool for use in the pharmaceutical sciences.

  17. [Nondestructive applanation technique to measure the elasticity moduli and creep properties of ocular cornea in vivo].

    PubMed

    Zhang, Xueyong; Liu, Dong; Tang, Zhen; Liao, Rongfeng; Ma, Jianguo

    2015-02-01

    Due to lack of the practical technique to measure the biomechanical properties of the ocular cornea in vivo, clinical ophthalmologists have some difficulties in understanding the deformation mechanism of the cornea under the action of physiological intraocular pressures. Using Young's theory analysis of the corneal deformation during applanation tonometry, the relation between the elasticity moduli of the cornea and the applanated corneal area and the measured and true intraocular pressures can be obtained. A new applanation technique has been developed for measuring the biomechanical properties of the ocular cornea tissue in vivo, which can simultaneously acquire the data of the applanation area and displacement of the corneal deformation as well as the exerted applanation force on the cornea. Experimental results on a rabbit's eyeball demonstrated that the present technique could be used to measure the elasticity moduli and creep properties of the ocular cornea nondestructively in vivo.

  18. NON-DESTRUCTIVE THERMAL BARRIER COATING SPALLATION PREDICTION BY A LOADBASED MICRO-INDENTATION TECHNIQUE

    SciTech Connect

    J. M. Tannenbaum; K. Lee; B. S.-J. Kang; M.A. Alvin

    2010-11-18

    Currently, the durability and life cycle of thermal barrier coatings (TBC) applied to gas turbine blades and combustor components are limiting the maximum temperature and subsequent efficiency at which gas turbine engines operate. The development of new materials, coating technologies and evaluation techniques is required if enhanced efficiency is to be achieved. Of the current ceramic coating materials used in gas turbine engines, yttria stabilized zirconia (YSZ) is most prevalent, its low thermal conductivity, high thermal expansion coefficient and outstanding mechanical strength make it ideal for use in TBC systems. However, residual stresses caused by coefficients of thermal expansion mismatches within the TBC system and unstable thermally grown oxides are considered the primary causes for its premature and erratic spallation failure. Through finite element simulations, it is shown that the residual stresses generated within the thermally grown oxide (TGO), bond coat (BC), YSZ and their interfaces create slight variations in indentation unloading surface stiffness response prior to spallation failure. In this research, seven air plasma sprayed and one electron beam physical vapor deposition yttria partially stabilized zirconia TBCs were subjected to isothermal and cyclic loadings at 1100°C. The associated coating degradation was evaluated using a non-destructive multiple partial unloading micro-indentation procedure. The results show that the proposed non-destructive micro-indentation evaluation technique can be an effective and specimenindependent TBC failure prediction tool capable of determining the location of initial spallation failure prior to its actual occurrence.

  19. Measurement techniques and application of electrical properties for nondestructive quality evaluation of foods-a review.

    PubMed

    Jha, Shyam Narayan; Narsaiah, K; Basediya, A L; Sharma, Rajiv; Jaiswal, Pranita; Kumar, Ramesh; Bhardwaj, Rishi

    2011-08-01

    Non-destructive systems are recent trends for quality evaluation of fruits and vegetables. Information on post-harvest variations in electrical properties is needed to develop new instruments for this purpose. Electrical properties are finding increasing application in agriculture and food processing industries. Knowledge of dielectric properties of foods as a function of moisture content and temperature is essential in the design and control of drying systems. As simple, rapid and non-destructive measuring techniques, dielectric spectroscopy provides information about the dielectric response of materials to electromagnetic field. Electrical properties of agricultural materials have been of interest for many years. The interest in dielectric properties of materials has historically been associated with the design of electrical equipment. This review paper covers theoretical aspects of different electrical properties, their measurement techniques, applications of dielectric properties in agriculture/food processing sector and potential applications of thermal imaging (TI) for quality and safety assessment in food processing. The values of dielectric properties of a number of products including food grains, fruits and vegetables, and meat and meat products are presented in table form. This comprehensive coverage will be useful for academic, scientific and industrial community in treating and applying the facts in developing/testing new processes and products based on electromagnetic energy application.

  20. Non-destructive techniques for the detection of fungal infection in cereal grains.

    PubMed

    Orina, Irene; Manley, Marena; Williams, Paul J

    2017-10-01

    Infection of cereal grains by fungi is a serious problem worldwide. Depending on the environmental conditions, cereal grains may be colonised by different species of fungi. These fungi cause reduction in yield, quality and nutritional value of the grain; and of major concern is their production of mycotoxins which are harmful to both humans and animals. Early detection of fungal contamination is an essential control measure for ensuring storage longevity and food safety. Conventional methods for detection of fungal infection, such as culture and colony techniques or immunological methods are either slow, labour intensive or difficult to automate. In recent years, there has been an increasing need to develop simple, rapid, non-destructive methods for early detection of fungal infection and mycotoxins contamination in cereal grains. Methods such as near infrared (NIR) spectroscopy, NIR hyperspectral imaging, and electronic nose were evaluated for these purposes. This paper reviews the different non-destructive techniques that have been considered thus far for detection of fungal infection and mycotoxins in cereal grains, including their principles, application and limitations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Application of non-destructive techniques to assess the state of Hagia Sophia's mosaics

    NASA Astrophysics Data System (ADS)

    Moropoulou, Antonia; Karoglou, Maria; Labropoulos, Kyriakos C.; Delegou, Ekaterini T.; Katsiotis, Nikolaos K.; Karagiannis-Bakolas, Asterios

    2012-04-01

    The church of Hagia Sophia in Istanbul is a world heritage monument that epitomizes the byzantine ecclesiastic architecture. The church is decorated with mosaics from various historic periods. The preservation state of the mosaics is of high importance. In this study, non-destructive techniques (ground penetrating radar, infra-red thermography, fibreoptics microscopy) were employed on south upper gallery mosaic areas. The main aim of this on-site investigation was the evaluation of the preservation state of the mosaics and the previous interventions (materials characterization and decay diagnosis) in order to assess the performance of previous conservation/restoration interventions, as well as to verify the presence of mosaics in layers below the external plaster surfaces. Results indicated that is indeed possible to locate the grid of rendered mosaics. Regarding the preservation state of the mosaics, it was indicated that the main environmental decay factors were the high relative humidity levels with co-action of salt damp as well as the air pollutants. Moreover, it was revealed that previous incompatible restoration/conservation interventions have often accelerated the mosaics' degradation processes. Using non-destructive techniques it was possible to identify areas where the mosaic materials (tesserae and mortars) presented decay problems and in addition identify sub-layers that pose risk of detachment or decay intensification. In this way, NDT can contribute to the development of a strategic planning for mosaics conservation, protection and revealing.

  2. Correlation-based imaging technique using ultrasonic transmit-receive array for Non-Destructive Evaluation.

    PubMed

    Quaegebeur, Nicolas; Masson, Patrice

    2012-12-01

    This paper describes a novel array post-processing method for Non-Destructive Evaluation (NDE) using phased-array ultrasonic probes. The approach uses the capture and processing of the full matrix of all transmit-receive time-domain signals from a transducer array as in the case of the Total Focusing Method (TFM), referred as the standard of imaging algorithms. The proposed technique is based on correlation of measured signals with theoretical propagated signals computed over a given grid of points. In that case, real-time imaging can be simply implemented using discrete signal product. The advantage of the present technique is to take into account transducer directivity, dynamics and complex propagation patterns, such that the number of required array elements for a given imaging performance can be greatly reduced. Numerical and experimental application to contact inspection of isotropic structure is presented and real-time implementation issues are discussed.

  3. Application of internal friction nondestructive evaluation technique for wire ropes used in mining operations

    SciTech Connect

    Olver, L.; Brasfield, R.G.; Yeager, L.L.; Thiruvengadam, A.P.

    1980-05-01

    This report discusses the work done, and results obtained, in a program conducted to determine the feasibility of applying the Internal Friction Damping - Nondestructive Evaluation (IFD-NDE) technique to wire rope. Samples of wire rope were evaluated in laboratory experiments by measuring the internal friction damping while varying several test parameters. These parameters included tensile load, frequency of test, time under load and others. The report includes discussion of wire rope mechanics and application history of NDE. Also included are sections detailing IFD-NDE theory, experimental apparatus, and test technique. The data obtained in the program work is reviewed with several results and conclusions drawn. The report closes with recommendations for further work.

  4. Use of an ultrasonic-acoustic technique for nondestructive evaluation of fiber composite strength

    NASA Technical Reports Server (NTRS)

    Vary, A.; Bowles, K. J.

    1978-01-01

    Details of the method used to measure the stress wave factor are described. Frequency spectra of the stress waves are analyzed in order to clarify the nature of the wave phenomena involved. The stress wave factor was measured with simple contact probes requiring only one-side access to a part. This is beneficial in nondestructive evaluations because the waves can run parallel to fiber directions and thus measure material properties in directions assumed by actual loads. The technique can be applied where conventional through transmission techniques are impractical or where more quantitative data are required. The stress wave factor was measured for a series of graphite/polyimide composite panels, and results obtained are compared with through transmission immersion ultrasonic scans.

  5. Guided wave technique for non-destructive testing of StifPipe

    NASA Astrophysics Data System (ADS)

    Amjad, Umar; Yadav, Susheel K.; Nguyen, Chi H.; Ehsani, Mohammad; Kundu, Tribikram

    2015-03-01

    The newly-developed StifPipe® is an effective technology for repair and strengthening of existing pipes and culverts. The wall of this pipe consists of a lightweight honeycomb core with carbon or glass fiber reinforced polymer (FRP) applied to the skin. The presence of the hollow honeycomb introduces challenges in the nondestructive testing (NDT) of this pipe. In this study, it is investigated if guided waves, excited by PZT (Lead ZirconateTitanate) transducer can detect damages in the honeycomb layer of the StifPipe®. Multiple signal processing techniques are used for in-depth study and understanding of the recorded signals. The experimental technique for damage detection in StifPipe® material is described and the obtained results are presented in this paper.

  6. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-4, Operation of Magnetic Particle Test Equipment.

    ERIC Educational Resources Information Center

    Groseclose, Richard

    This fourth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II describes the specific technique variables and options which are available to the test technician, provides instructions for selecting and operating the appropriate test equipment, describes physical criteria for detectable discontinuities,…

  7. Rapid non-destructive assessment of pork edible quality by using VIS/NIR spectroscopic technique

    NASA Astrophysics Data System (ADS)

    Zhang, Leilei; Peng, Yankun; Dhakal, Sagar; Song, Yulin; Zhao, Juan; Zhao, Songwei

    2013-05-01

    The objectives of this research were to develop a rapid non-destructive method to evaluate the edible quality of chilled pork. A total of 42 samples were packed in seal plastic bags and stored at 4°C for 1 to 21 days. Reflectance spectra were collected from visible/near-infrared spectroscopy system in the range of 400nm to 1100nm. Microbiological, physicochemical and organoleptic characteristics such as the total viable counts (TVC), total volatile basic-nitrogen (TVB-N), pH value and color parameters L* were determined to appraise pork edible quality. Savitzky-Golay (SG) based on five and eleven smoothing points, Multiple Scattering Correlation (MSC) and first derivative pre-processing methods were employed to eliminate the spectra noise. The support vector machines (SVM) and partial least square regression (PLSR) were applied to establish prediction models using the de-noised spectra. A linear correlation was developed between the VIS/NIR spectroscopy and parameters such as TVC, TVB-N, pH and color parameter L* indexes, which could gain prediction results with Rv of 0.931, 0.844, 0.805 and 0.852, respectively. The results demonstrated that VIS/NIR spectroscopy technique combined with SVM possesses a powerful assessment capability. It can provide a potential tool for detecting pork edible quality rapidly and non-destructively.

  8. Developing nondestructive techniques for managing conflicts between fisheries and double-crested cormorant colonies

    USGS Publications Warehouse

    Suzuki, Yasuko; Roby, Daniel D.; Lyons, Donald E.; Courtot, Karen; Collis, Ken

    2015-01-01

    Double-crested cormorants (Phalacrocorax auritus) have been identified as the source of significant mortality to juvenile salmonids (Oncorhynchus spp.) in the Columbia River Basin. Management plans for reducing the size of a large colony on East Sand Island (OR, USA) in the Columbia River estuary are currently being developed. We evaluated habitat enhancement and social attraction as nondestructive techniques for managing cormorant nesting colonies during 2004–2007. We tested these techniques on unoccupied plots adjacent to the East Sand Island cormorant colony. Cormorants quickly colonized these plots and successfully raised young. Cormorants also were attracted to nest and raised young on similar plots at 2 islands approximately 25 km from East Sand Island; 1 island had a history of successful cormorant nesting whereas the other was a site where cormorants had previously nested unsuccessfully. On a third island with no history of cormorant nesting or nesting attempts, these techniques were unsuccessful at attracting cormorants to nest. Our results suggest that some important factors influencing attraction of nesting cormorants using these techniques include history of cormorant nesting, disturbance, and presence of breeding cormorants nearby. These techniques may be effective in redistributing nesting cormorants away from areas where fish stocks of conservation concern are susceptible to predation, especially if sites with a recent history of cormorant nesting are available within their foraging or dispersal range. Published 2015. Wiley Periodicals, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.

  9. Non-Destructive Survey of Archaeological Sites Using Airborne Laser Scanning and Geophysical Applications

    NASA Astrophysics Data System (ADS)

    Poloprutský, Z.; Cejpová, M.; Němcová, J.

    2016-06-01

    This paper deals with the non-destructive documentation of the "Radkov" (Svitavy district, Czech Republic) archaeological site. ALS, GPR and land survey mapping will be used for the analysis. The fortified hilltop settlement "Radkov" is an immovable historical monument with preserved relics of anthropogenic origin in relief. Terrain reconnaissance can identify several accentuated objects on site. ALS enables identification of poorly recognizable archaeological objects and their contexture in the field. Geophysical survey enables defunct objects identification. These objects are hidden below the current ground surface and their layout is crucial. Land survey mapping provides technical support for ALS and GPR survey. It enables data georeferencing in geodetic reference systems. GIS can then be used for data analysis. M. Cejpová and J. Němcová have studied this site over a long period of time. In 2012 Radkov was surveyed using ALS in the project "The Research of Ancient Road in Southwest Moravia and East Bohemia". Since 2015 the authors have been examining this site. This paper summarises the existing results of the work of these authors. The digital elevation model in the form of a grid (GDEM) with a resolution 1 m of 2012 was the basis for this work. In 2015 the survey net, terrain reconnaissance and GPR survey of two archaeological objects were done at the site. GDEM was compared with these datasets. All datasets were processed individually and its results were compared in ArcGIS. This work was supported by the Grant Agency of the CTU in Prague, grant No. SGS16/063/OHK1/1T/11.

  10. Contamination of Outer Surfaces of International Space Station Studied by Non-Destructive Techniques

    NASA Astrophysics Data System (ADS)

    Borisov, V. A.; Naumov, S. F.; Sokolova, S. P.; Kurilenok, A. O.; Skurat, V. E.; Zhigach, A. N.; Beriozkina, N. G.; Leipunsky, I. O.; Pshechenkov, P. A.; Zotova, E. S.; Volkov, I. O.; Naumkin, A. V.; Artemov, V. V.

    The aim of this work is to study non -volatile components of contamination deposits on outer surfaces of International Space Station (Russian segment) by a complex of non-destructive techniques - X-ray photoelectron spectroscopy (XPS), diffuse reflection infrared spectroscopy, scanning electron microscopy and local X-ray microanalysis (LXMA). These methods were used for investigation of 40 samples of materials and coatings after their exposure to residual atmosphere of Earth and external conditions of spacecraft. Elemental and chemical composition of surface and sub-surface layers is varied in very broad limits due to concurrence of many processes changing the sample composition. Contamination deposits contain nitrogenous components besides ubiquitous carbonaceous and siliceous components that are typical for spacecraft surface contamination.

  11. Main geophysical techniques used for non-destructive evaluation in cultural built heritage: a review

    NASA Astrophysics Data System (ADS)

    Martinho, E.; Dionísio, A.

    2014-10-01

    Geophysical methodologies have been implemented, tested and validated as diagnostic and /or monitoring tools in artworks or historical monuments. They are non-destructive and can give an image of internal structure of investigated medium. This paper is a review about the main geophysical techniques applied to the study of cultural built heritage (excluding the archaeology field). A brief description of the used methodologies is presented, the main investigations done in this field are showed, the method or methods most appropriate to answer each problem (moisture detection, characterization of the materials, study of the structural continuity of the material, assessment of intervention’s effectiveness) are indicated and the main advances and gaps and future developments are also pointed out.

  12. Nondestructive evaluation techniques for development and characterization of carbon nanotube based superstructures

    NASA Astrophysics Data System (ADS)

    Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

    2015-03-01

    Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns [1]. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking [2]. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-to-weight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

  13. Neutron measurement techniques for the nondestructive analysis of irradiated fuel assemblies

    SciTech Connect

    Phillips, J.R.; Bosler, G.E.; Halbig, J.K.; Klosterbuer, S.F.; Lee, D.M.; Menlove, H.O.

    1981-11-01

    Nondestructive measurement of the passive neutron signatures of irradiated light-water reactor fuel assemblies is a rapid and simple technique for verifying operator-declared exposure values. Fuel assemblies from four different reactor facilities have been measured to establish the functional relationship between the operator-declared exposure values and the experimentally measured neutron emission rates. Experimentally measured neutron emission rates of small fuel rod sections have been shown to agree with the predicted results from our calculational model. Destructive results for the actinide isotopes also agreed very well with our prediction. Neutron emission rates varied by 30 to 40% between opposite corners of the source fuel assembly. Symmetrical neutron detector systems that measure all sides simultaneously were evaluated.

  14. Nondestructive Evaluation Techniques for Development and Characterization of Carbon Nanotube Based Superstructures

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

    2014-01-01

    Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-toweight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter, defect ratio, and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

  15. Multi-isotopic transuranic waste interrogation using delayed neutron nondestructive assay and iterative quadratic programming techniques

    NASA Astrophysics Data System (ADS)

    Wu, Cheng-Wei

    1997-11-01

    Nuclear safeguards for Special Nuclear Materials is to protect the nuclear materials against malevolent use and to insure their peaceful usage. The nondestructive assay technique (NDA) offers an efficient and proliferation resistance method for nuclear safeguards technology. NDA techniques were investigated for multi-isotopic transuranic waste interrogation. This work was originally intended for the Integral Fast Reactor (IFR) under development at Argonne National Laboratory. One major feature of the IFR is its integral fuel cycle based on a pyrometallurgical process. More than 99% of transuranics produced in the fuel are returned to the makeup fuel and burned in the reactor. With the long-lived actinides removed from the waste stream, the waste produced will decay sufficiently in 300 years dropping below the cancer risk level of natural uranium ore and easing the perceived waste management problem. The feasibility of using nondestructive assay techniques for the IFR fuel cycle waste interrogation were studied. A special DNNDA experimental device was designed and analysis techniques were developed. The DNNDA technique uses the delayed neutrons emitted after the activation of a 14 MeV neutron source as the characteristic signature for each fissionable isotope. A tantalum/polyethylene filter was employed to enhance the discrimination between the fissile and the fissionable isotopes. Spontaneous fissions from 240Pu were also measured to assist the mass assay. A nonlinear overdetermined system was established based on the DNNDA measurements. An Iterative Quadratic Programming (IQP) method was applied to perform the estimates. The IQP method has several advantages over the linear least squares and Kalman filter methods, it has the flexibility of adding additional constraints, it has superlinear global convergence and it can be utilized for nonlinear problems. The results show that using the IQP method with the DNNDA technique is quite promising for multi-isotopic assay

  16. An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

    NASA Technical Reports Server (NTRS)

    Cosgriff, Laura M.; Roberts, Gary D.; Binienda, Wieslaw K.; Zheng, Diahua; Averbeck, Timothy; Roth, Donald J.; Jeanneau, Philippe

    2006-01-01

    Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

  17. The application of nondestructive techniques to the testing of a wind turbine blade

    SciTech Connect

    Sutherland, H.J.; Musial, W.

    1993-07-01

    NonDestructive Testing (NDT) is commonly used to monitor structures before, during and after testing. This paper reports on the use of two NDT techniques to monitor the behavior of a typical wind turbine blade during a quasi-static test-to-failure. The test used a three-point spanwise load distribution to load a 7.9-m blade to failure. The two NDT techniques used were acoustic emission and coherent optical. The former monitors the acoustic energy produced by the blade as it is loaded. The latter uses electronic shearography to measure the differences in surface displacements between two load states with an accuracy of a few microns. Typical results are presented to demonstrate the ability of these two techniques to locate and monitor both high damage regions and flaws in the blade structure. Further, this experiment highlights the limitations in the techniques that must be addressed before one or both can be transferred, with a high probability of success, to the inspection and monitoring of turbine blades during the manufacturing process and under normal operating conditions.

  18. The Development and Application of Nondestructive Testing Techniques for Evaluating High Temperature Protective Coatings.

    DTIC Science & Technology

    TURBINE BLADES, REFRACTORY COATINGS), (*REFRACTORY COATINGS, NONDESTRUCTIVE TESTING), GAS TURBINES, SLURRY COATING, REFRACTORY METAL ALLOYS, NIOBIUM, SILICIDES, DEFECTS(MATERIALS), EROSIVE BURNING, SEEBECK EFFECT , TOLERANCES(MECHANICS), RADIOGRAPHY.

  19. Development of non-destructive quality measurement technique for cabbage seed (Brassica campestris L) using hyperspectral reflectance imaging

    USDA-ARS?s Scientific Manuscript database

    Cabbage (Brassica campestris L) is an important crop for Asian countries especially in Korea, Japan and China. In order to achieve uniform and high-yield rate of cabbage product, the seed lot quality needs to be controlled. Non-destructive evaluation of seed viability is an important technique for i...

  20. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-7, Radiographic Specifications and Code Requirements.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This seventh in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes radiographic specifications and code requirements. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  1. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-1, Fundamentals of Ultrasonic Testing.

    ERIC Educational Resources Information Center

    Spaulding, Bruce

    This first in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II introduces the student/trainee to the basic behavior of ultrasound, describes ultrasonic test equipment, and outlines the principal methods of ultrasonic testing. The module follows a typical format that includes the following sections: (1)…

  2. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-2, Operation of Ultrasonic Test Equipment.

    ERIC Educational Resources Information Center

    Espy, John

    This second in a series of six modules for a course titled Nondestructive Examination (NDE) II describes specific ultrasonic test techniques and calibration principles. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  3. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-5, Fundamentals of Eddy Current Testing.

    ERIC Educational Resources Information Center

    Espy, John

    This fifth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II describes the fundamental concepts applicable to eddy current testing in general. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to…

  4. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-7, Radiographic Specifications and Code Requirements.

    ERIC Educational Resources Information Center

    Pelton, Rick; Espy, John

    This seventh in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes radiographic specifications and code requirements. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  5. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-6, Operation of Eddy Current Test Equipment.

    ERIC Educational Resources Information Center

    Espy, John; Selleck, Ben

    This sixth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II details eddy current examination of steam generator tubing. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  6. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-5, Fundamentals of Eddy Current Testing.

    ERIC Educational Resources Information Center

    Espy, John

    This fifth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II describes the fundamental concepts applicable to eddy current testing in general. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to…

  7. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-6, Operation of Eddy Current Test Equipment.

    ERIC Educational Resources Information Center

    Espy, John; Selleck, Ben

    This sixth in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II details eddy current examination of steam generator tubing. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  8. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-2, Operation of Ultrasonic Test Equipment.

    ERIC Educational Resources Information Center

    Espy, John

    This second in a series of six modules for a course titled Nondestructive Examination (NDE) II describes specific ultrasonic test techniques and calibration principles. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  9. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-1, Fundamentals of Ultrasonic Testing.

    ERIC Educational Resources Information Center

    Spaulding, Bruce

    This first in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II introduces the student/trainee to the basic behavior of ultrasound, describes ultrasonic test equipment, and outlines the principal methods of ultrasonic testing. The module follows a typical format that includes the following sections: (1)…

  10. Nondestructive measurement of reducing sugar of apples using Vis/NIR spectroscopy techniques

    NASA Astrophysics Data System (ADS)

    Jiang, Yihong; Li, Xiaoli; Bai, Xiujun; He, Yong

    2006-09-01

    In this research, the potential ofusing the Visible/Near Infrared Spectroscopy (VisINIRS) was investigated for measuring the reducing sugar of Fuji apple (from Shanxi of China), and the relationship was established between nondestructive Vis/NIR spectral measurement and the reducing sugar of apple. Intact apple fruit were measured by reflectance Vis/NIR in 325-1075 nm range. The data set as the logarithms of the reflectance reciprocal (absorbance (logl/R)) was analyzed in order to build the best calibration model for this characteristic, using some spectral pretreatments and multivariate calibration techniques such as partial least square regression (PLS). The models for the reducing sugar (r=0.915), standard error ofprediction (SEP) 0.562 with a bias of 0.054; shown the excellent prediction performance. The Vis/NIR spectroscopy technique had significantly greater accuracy for determining the reducing sugar. It was concluded that by using the Vis/NIRS measurement technique, in the spectral range (325-1075 nm), it is possible to assess the reducing sugar content of apple.

  11. On-line monitoring of lead-acid batteries by galvanostatic non-destructive technique

    NASA Astrophysics Data System (ADS)

    Hariprakash, B.; Martha, S. K.; Jaikumar, Arthi; Shukla, A. K.

    Measurements of charge-acceptance, internal resistance, voltage and self-discharge of a battery reflect its state-of-health (SOH). The galvanostatic non-destructive technique (GNDT) can be used to monitor the SOH of a battery by analyzing its impedance parameters, namely ohmic resistance, charge-transfer resistance and interfacial capacitance. In this technique, the battery is discharged galvanostatically at a substantially low-rate over a short duration, wherein the state-of-charge (SOC) of the battery is not affected. It has been possible to obtain charge-transfer resistance and double-layer capacitance values for both positive and negative plates of a commercial grade 6-V/4-Ah valve-regulated lead-acid battery during its dynamic discharge. The resistive components of the battery are found to be minimum at state-of-charge values between 0.2 and 0.9. The study shows that the optimum performance of the VRLA battery can be achieved at SOC values between 0.2 and 0.9. The ohmic resistance of the battery displays a linear variation with logarithmic values of its SOC. The technique provides an attractive tool for on-line monitoring of lead-acid batteries.

  12. Development and validation of nondestructive inspection techniques for composite doubler repairs on commercial aircraft

    SciTech Connect

    Roach, D.; Walkington, P.

    1998-05-01

    Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single boron-epoxy composite doubler to the damaged structure. In order for the use of composite doublers to achieve widespread use in the civil aviation industry, it is imperative that methods be developed which can quickly and reliably assess the integrity of the doubler. In this study, a specific composite application was chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Primary among inspection requirements for these doublers is the identification of disbonds, between the composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the doubler is also a concern. No single nondestructive inspection (NDI) method can inspect for every flaw type, therefore it is important to be aware of available NDI techniques and to properly address their capabilities and limitations. A series of NDI tests were conducted on laboratory test structures and on full-scale aircraft fuselage sections. Specific challenges, unique to bonded composite doubler applications, were highlighted. An array of conventional and advanced NDI techniques were evaluated. Flaw detection sensitivity studies were conducted on applicable eddy current, ultrasonic, X-ray and thermography based devices. The application of these NDI techniques to composite doublers and the results from test specimens, which were loaded to provide a changing flaw profile, are presented in this report. It was found that a team of these techniques can identify flaws in composite doubler installations well before they reach critical size.

  13. Non-destructive evaluation of concrete with ultrasonic C-scan and digital image enhancement techniques

    NASA Astrophysics Data System (ADS)

    Okafor, A. Chukwujekwu; Dutta, Amitabha

    2014-02-01

    This paper presents the results of Non-Destructive Evaluation (NDE) of concrete slabs using Ultrasonic C-Scan and image-enhancement algorithms for the detection and extraction of damage information from raw data. Two fabricated concrete slabs, one undamaged and the other with three rectangular voids were used for the test. Damage was evaluated by using ultrasonic through transmission C-Scan method. A 500 kHz transducer with pulse rates of 100 Hz to 5000 Hz was investigated to determine the best pulse rate for scanning concrete. The amplitude scan shows accurately the position of the voids present in the damaged concrete with respect to the reference edge. The results also show the inherent in-homogeneity of the concrete slab due to the presence of air pockets that invariably arise during the fabrication. Three statistical filtering techniques (Median, Mean and Gaussian) and one wavelet filtering technique were comparatively evaluated to enhance the quality of the digital image. The results show clearly the presence of the rectangular voids. Median filtering technique was the best in enhancing the image obtained from the C-Scan in terms of removing noise and preserving the details of the defects. Wavelet filtering technique was good in terms of overall noise reduction, but it resulted in loss of details of the defects producing a comparatively blurred image. This technique can be used to determine the quality of concrete at any stage in its working lifecycle thus making it a useful tool in the field of health monitoring of concrete.

  14. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1998-01-01

    An overall goal of this research has been to enhance our understanding of the scientific principles necessary to develop advanced ultrasonic nondestructive techniques for the quantitative characterization of advanced composite structures. To this end, we have investigated a thin woven composite (5-harness biaxial weave). We have studied the effects that variations of the physical parameters of the experimental setup can have on the ultrasonic determination of the material properties for this thin composite. In particular, we have considered the variation of the nominal center frequency and the f-number of the transmitting transducer which in turn address issues such as focusing and beam spread of ultrasonic fields. This study has employed a planar, two-dimensional, receiving pseudo-array that has permitted investigation of the diffraction patterns of ultrasonic fields. Distortion of the ultrasonic field due to the spatial anisotropy of the thin composite has prompted investigation of the phenomenon of phase cancellation at the face of a finite-aperture, piezoelectric receiver. We have performed phase-sensitive and phase-insensitive analyses to provide a measure of the amount of phase cancellation at the face of a finite-aperture, piezoelectric receiver. The pursuit of robust measurements of received energy (i.e., those not susceptible to phase cancellation at the face of a finite-aperture, piezoelectric receiver) supports the development of robust techniques to determine material properties from measure ultrasonic parameters.

  15. Application of laser ultrasonic non-destructive evaluation technique to additive manufacturing

    NASA Astrophysics Data System (ADS)

    Manzo, Anthony J.; Kenderian, Shant; Helvajian, Henry

    2016-04-01

    The change in properties of a propagating ultrasonic wave has been a mainstay characterization tool of the nondestructive evaluation (NDE) industry for identifying subsurface defects (e.g. damage). A variant of this concept could be applicable to 3D additive manufacturing where the existence of defects (e.g. pores) within a sub-layer could mark a product as non-qualifying. We have been exploring the utility of pulsed laser ultrasonic excitation coupled with CW laser heterodyne detection as an all optical scheme for characterizing sub surface layer properties. The all-optical approach permits a straight forward integration into a laser additive processing tool. To test the concept, we have developed an experimental system that generates pulsed ultrasonic waves (the probe) with high bandwidth (<<10MHz) and a surface displacement sensor that can capture the ultrasonic "return" signal with bandwidth close to 300 MHz. The use of high frequencies enables the detection of smaller defect sites. The technique is time resolved with the sensor and probe as point (>>30-200 microns) beams. Current tests include characterizing properties of spot weld joints between two thin stainless steel plates. The long term objective is to transition the technique into a laser additive manufacturing tool.

  16. NONDESTRUCTIVE DETECTION OF DELAMINATION IN THERMAL BARRIER COATINGS USING ULTRASONIC TECHNIQUE

    SciTech Connect

    Chen, Roger H. L.; Zhang, Binwei; Alvin, Mary Anne

    2009-06-12

    Nondestructive testing using an acousto-ultrasonic technique has been utilized to detect the change of material properties and provide early warning of failure of thermal barrier coating (TBC) systems. Testing was performed on René N5 and Haynes 230 coupons with an applied NETL-bond coat, as well as on coupons containing both an applied MCrAlY bond coat and 7-YSZ top coat. The coupons were subjected to either cyclic or isothermal testing at 1100ºC. Ultrasonic testing was performed before and after thermal testing using piezoelectric sensors with dry contact on the surface of the coatings. Proof-of-concept test results indicated that changes in the properties of the 40m bond coat can be detected using the proposed technique. Waveforms generated via Pitch/Catch indicated minor changes within the bond coat applied to René N5 substrate after 400500 hours of cyclic oxidation at 1100°C. In contrast, marked differences in waveforms and travel time reflected significant crack formation and spallation of the bond coat from the Haynes 230 substrate. Finite element analysis (FEA) simulation of the wave propagation on a simplified TBC system with nonlinear effects was conducted. FEA results clearly show detection of a small embedded void incorporated to simulate delamination. Comparisons between experimental measurements and finite element simulations were used to estimate the material properties of the coatings and the substrate.

  17. First-time observation of Mastro Giorgio masterpieces by means of non-destructive techniques

    NASA Astrophysics Data System (ADS)

    Padeletti, G.; Ingo, G. M.; Bouquillon, A.; Pages-Camagna, S.; Aucouturier, M.; Roehrs, S.; Fermo, P.

    2006-06-01

    For the first time some excellent pieces belonging to the majolica production of the great master Giorgio Andreoli from Gubbio (Central Italy) have been characterized from a chemical and structural point of view with the aim to identify the composition of both pigments and lustres. A series of particle-induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and Raman analyses have been performed on some plates coming from Museo del Palazzo dei Consoli (Gubbio) and several French museums (Louvre, Musée National de la Céramique, Musée National de la Renaissance) lustred by Giorgio Andreoli and decorated by famous majolica painters such as Francesco Xanto Avelli. The three techniques are complementary and useful in the investigation of art objects since they are non-destructive. Furthermore, the low detection limits allow the identification of all elements and compounds present, and RBS allows concentration profiling, too. It is worth noticing that the examined objects are characterized by the presence of both gold and ruby-red lustres, a peculiarity of Mastro Giorgio’s technique. The measurements by PIXE and RBS have been carried out on the AGLAE accelerator at C2RMF, Louvre Palace.

  18. Non-destructive study of wood using the Compton scattering technique.

    PubMed

    Tondon, Akash; Singh, Mohinder; Sandhu, B S; Singh, Bhajan

    2017-11-01

    A simple nondestructive method is presented in this study to characterize woods having different densities, thus estimating the size and depth of inhomogeneities in given wood samples using the Compton scattering technique (CST). This technique uses a collimated beam of 662-keV energy from (137)Cs radioactive source, and the scattered flux is detected by an NaI(Tl) detector. To characterize different wood samples on the basis of their densities, both scattering and transmission experiments were performed. The presence of inhomogeneities such as knots in wood was simulated by drilling cylindrical voids of diameter 9mm in the samples and then filling them with a high-density material (aluminum). Furthermore, different sizes of inhomogeneities (Al cylinders) were filled in the wood samples to estimate the depth and size of the inhomogeneity using the CST. A higher linear correlation (R(2) ~ 0.96) was found between the scattered intensity and the density of different woods using the CST than that using the transmission (R(2) ~ 0.83) method by measuring the density range. An increase of 24.6% in the average scattered intensity was observed at the location where the knot was present, and it was found that an inhomogeneity of the order of ~4mm or more could be detected by the CST. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The use of portable Non-Destructive Techniques for material decay characterisation of palaeontological Geosites

    NASA Astrophysics Data System (ADS)

    Gomez-Heras, Miguel; Ortega-Becerril, Jose A.; López-Martínez, Jerónimo; Oliva-Urcia, Belén; Maestro, Adolfo

    2017-04-01

    The conservation of both natural and cultural heritage is regarded as a priority for humankind and it is therefore recognised by the UNESCO since the Convention Concerning the Protection of the World Cultural and Natural Heritage in 1972. The International Union of Geological Sciences launched in 1995 in collaboration with UNESCO the Global Geosites programme to create an inventory of geological heritage sites. Although the conservation of Geosites may face different issues to those of stone-built cultural heritage, much could be learnt from techniques initially used to characterise weathering and material decay in stone-built cultural heritage. This is especially the case for portable Non-Destructive Techniques (NDT). Portable NDT allow characterising on-site the degree of material decay and are, therefore, a good way to assess the state of conservation of certain Geosites whose relevance lies on localised features. Geosites chosen for the outstanding occurrence of dinosaur ichnites, such as those in the Cameros Massif (north-western part of the Iberian Range, Spain), are a good example of this. This communication explores the potential of portable NDT to characterise the state of decay and susceptibility to further decay of dinosaur ichnites in the Cameros Massif. These techniques included: Ultrasound Pulse Velocity determination, Leeb hardness rebound test, colour determination by means of a spectrophotometer and thermal imaging obtained with an infrared camera. Results will show the potential of these techniques to characterise differential weathering patterns in both individual ichnites as well as on tracks in addition to assessing the possible effects of conservation strategies on the long-term preservation of the mentioned Geosites. Research funded by Madrid's Regional Government project Geomateriales 2 S2013/MIT-2914

  20. Determining Plutonium Mass in Spent Fuel with Nondestructive Assay Techniques -- Preliminary Modeling Results Emphasizing Integration among Techniques

    SciTech Connect

    Tobin, S. J.; Fensin, M. L.; Ludewigt, B. A.; Menlove, H. O.; Quiter, B. J.; Sandoval, N. P.; Swinhoe, M. T.; Thompson, S. J.

    2009-08-03

    There are a variety of motivations for quantifying Pu in spent (used) fuel assemblies by means of nondestructive assay (NDA) including the following: strengthen the capabilities of the International Atomic Energy Agencies to safeguards nuclear facilities, quantifying shipper/receiver difference, determining the input accountability value at reprocessing facilities and providing quantitative input to burnup credit determination for repositories. For the purpose of determining the Pu mass in spent fuel assemblies, twelve NDA techniques were identified that provide information about the composition of an assembly. A key point motivating the present research path is the realization that none of these techniques, in isolation, is capable of both (1) quantifying the elemental Pu mass of an assembly and (2) detecting the diversion of a significant number of pins. As such, the focus of this work is determining how to best integrate 2 or 3 techniques into a system that can quantify elemental Pu and to assess how well this system can detect material diversion. Furthermore, it is important economically to down-select among the various techniques before advancing to the experimental phase. In order to achieve this dual goal of integration and down-selection, a Monte Carlo library of PWR assemblies was created and is described in another paper at Global 2009 (Fensin et al.). The research presented here emphasizes integration among techniques. An overview of a five year research plan starting in 2009 is given. Preliminary modeling results for the Monte Carlo assembly library are presented for 3 NDA techniques: Delayed Neutrons, Differential Die-Away, and Nuclear Resonance Fluorescence. As part of the focus on integration, the concept of"Pu isotopic correlation" is discussed and the role of cooling time determination.

  1. Nondestructive evaluation of metal and composite targets using an infrared line-scanning technique

    NASA Astrophysics Data System (ADS)

    Smith, Christopher; Rowley, Matthew; Dvonch, Curt; Fulton, Mary

    2005-03-01

    A thermal, non-destructive evaluation (NDE) technique has been employed by ThermTech Services, Inc. in cooperation with NASA Langley Research Center that allows for quantitative measurements of wall thickness in steam boilers. By determining the thickness of the walls, one can easily determine how much thinning has occurred due to corrosion. This type of NDE can be applied to the inspection of wings and fuselages on aircraft and spaceflight vehicles including the shuttle. The NDE technique employs the linear movement of a heat source (lamp) and an infrared imager that is situated at a fixed distance behind the heat source. The instruments are aligned on a platform that moves up and down across the outer surface of a test sample. By analyzing the induced surface temperature variations, and processing images collected with the infrared imager, it can be determined where material loss of the tubes has occurred. After an image sequence has been collected, a line-by-line subtraction methodology is utilized to discard irrelevant information so that defects are displayed in a re-created image. The overall goal of this project is to provide a proof of concept for a portable, hand-operated thermographic line scanner that would provide an alternative to the existing mass- and power-intensive instrument that utilizes a cooled infrared imager. In this project, two different microbolometers are first analyzed using different metal- and carbon epoxy-based targets to determine which provides better resolution for detection of subsurface, manufactured defects. The feasibility of using uncooled bolometer technology to support the development of a portable instrument to conduct this type of NDE technique was proven.

  2. Characterization of hydroxypropylmethylcellulose films using microwave non-destructive testing technique.

    PubMed

    Anuar, Nor Khaizan; Wui, Wong Tin; Ghodgaonkar, Deepak K; Taib, Mohd Nasir

    2007-01-17

    The applicability of microwave non-destructive testing (NDT) technique in characterization of matrix property of pharmaceutical films was investigated. Hydroxypropylmethylcellulose and loratadine were selected as model matrix polymer and drug, respectively. Both blank and drug loaded hydroxypropylmethylcellulose films were prepared using the solvent-evaporation method and were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using microwave NDT technique as well as ultraviolet spectrophotometry, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) techniques. The results indicated that blank hydroxypropylmethylcellulose film exhibited a greater propensity of polymer-polymer interaction at the O-H and C-H domains of the polymer chains upon conditioned at a lower level of relative humidity. In the case of loratadine loaded films, a greater propensity of polymer-polymer and/or drug-polymer interaction via the O-H moiety was mediated in samples conditioned at the lower level of relative humidity, and via the C-H moiety when 50% relative humidity was selected as the condition for sample storage. Apparently, the absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer and/or drug-polymer interaction involving the O-H and C-H moieties. The measurement of microwave NDT test at 8GHz was sensitive to the chemical environment involving O-H moiety while it was greatly governed by the C-H moiety in test conducted at a higher frequency band of microwave. Similar observation was obtained with respect to the profiles of microwave NDT measurements against the state of polymer-polymer and/or drug-polymer interaction of hydroxypropylmethylcellulose films containing chlorpheniramine maleate. The microwave NDT measurement is potentially suitable for use as an apparent indicator of the state of polymer-polymer and drug

  3. Nondestructive characterization of thermal barrier coating by noncontact laser ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Chen, Jianwei; Zhang, Zhenzhen

    2015-09-01

    We present the application of a laser ultrasonic technique in nondestructive characterization of the bonding layer (BL) in a thermal barrier coating (TBC). A physical mode of a multilayered medium is established to describe the propagation of a longitudinal wave generated by a laser in a TBC system. Furthermore, the theoretical analysis on the ultrasonic transmission in TBC is carried out in order to derive the expression of the BL transmission coefficient spectrum (TCS) which is used to determine the velocity of the longitudinal wave in the BL. We employ the inversion method combined with TCS to ascertain the attenuation coefficient of the BL. The experimental validations are performed with TBC specimens produced by an electron-beam physical vapor deposition method. In those experiments, a pulsed laser with a width of 10 ns is used to generate an ultrasonic signal while a two-wave mixing interferometer is created to receive the ultrasonic signals. By introducing the wavelet soft-threshold method that improves the signal-to-noise ratio, the laser ultrasonic testing results of TBC with an oxidation of 1 cycle, 10 cycles, and 100 cycles show that the attenuation coefficients of the BL become larger with an increase in the oxidation time, which is evident for the scanning electron microscopy observations, in which the thickness of the thermally grown oxide increases with oxidation time.

  4. Microwave non-destructive testing technique for characterization of HPMC-PEG 3000 films.

    PubMed

    Wong, T W; Deepak, K G; Taib, M N; Anuar, N K

    2007-10-01

    The capacity of microwave non-destructive testing (NDT) technique to characterize the matrix property of binary polymeric films for use as transdermal drug delivery system was investigated. Hydroxypropylmethylcellulose (HPMC) and polyethylene glycol (PEG) 3000 were the choice of polymeric matrix and plasticizer, respectively with loratadine as the model drug. Both blank and drug loaded HPMC-PEG 3000 films were prepared using the solvent-evaporation method. These films were conditioned at the relative humidity of 25, 50 and 75% prior to physicochemical characterization using the established methods of ultra-violet spectrophotometry, differential scanning calorimetry and Fourier transform infrared spectroscopy methods, as well as, novel microwave NDT technique. Blank films exhibited a greater propensity of polymer-polymer interaction at the O-H domain upon storage at a lower level of relative humidity, whereas drug loaded films exhibited a greater propensity of polymer-polymer, polymer-plasticizer and/or drug-polymer interaction via the O-H, C-H and/or aromatic C=C functional groups when they were stored at a lower or moderate level of relative humidity. The absorption and transmission characteristics of both blank and drug loaded films for microwave varied with the state of polymer-polymer, polymer-plasticizer, and/or drug-polymer interaction of the matrix. The measurements of microwave NDT test at 8 and 12 GHz were sensitive to the polar fraction of film involving functional group such as O-H moiety and the less polar environment of matrix consisting of functional groups such as C-H and aromatic C=C moieties. The state of interaction between polymer, plasticizer and/or drug of a binary polymeric film can be elucidated through its absorption and transmission profiles of microwave.

  5. Nondestructive Evaluation of Adhesively Bonded Joints by Acousto-Ultrasonic Technique and Acoustic Emission

    NASA Technical Reports Server (NTRS)

    Nayeb-Hashemi, Hamid; Rossettos, J. N.

    1997-01-01

    Reliable applications of adhesively bonded joints require an effective nondestructive evaluation technique for their bond strength prediction. To properly evaluate factors affecting bond strength, effects of defects such as voids and disbonds on stress distribution in the overlap region must be understood. At the same time, in order to use acousto-ultrasonic (AU) technique to evaluate bond quality, the effect of these defects on dynamic response of single lap joints must be clear. The stress distribution in a single lap joint with and without defects (void or disbond) is analyzed. A bar-Theta parameter which contains adherend and adhesive thickness and properties is introduced. It is shown for bonded joints with bar-Theta greater than 10, that a symmetric void or disbond in the middle of overlap up to the 70 percent of overlap length has negligible effect on bond strength. In contrast frequency response analyses by a finite element technique showed that the dynamic response is affected significantly by the presence of voids or disbonds. These results have direct implication in the interpretations of AU results. Through transmission attenuation and a number of AU parameters for various specimens with and without defects are evaluated. It is found that although void and disbond have similar effects on bond strength (stress distribution), they have completely different effects on wave propagation characteristics. For steel-adhesive-steel specimens with voids, the attenuation changes are related to the bond strength. However, the attenuation changes for specimens with disbond are fairly constant over a disbond range. In order to incorporate the location of defects in AU parameters, a weighting function is introduced. Using an immersion system with focused transducers, a number of AU parameters are evaluated. It is found that by incorporating weighting functions in these parameters better sensitivities (AU parameters vs. bond strength) are achieved. Acoustic emission

  6. An accurate method for determining residual stresses with magnetic non-destructive techniques in welded ferromagnetic steels

    NASA Astrophysics Data System (ADS)

    Vourna, P.

    2016-03-01

    The scope of the present research work was to investigate the proper selection criteria for developing a suitable methodology for the accurate determination of residual stresses existing in welded parts. Magnetic non-destructive testing took place by the use of two magnetic non-destructive techniques: by the measurement of the magnetic Barkhausen noise and by the evaluation of the magnetic hysteresis loop parameters. The spatial distribution of residual stresses in welded metal parts by both non-destructive magnetic methods and two diffraction methods was determined. The conduction of magnetic measurements required an initial calibration of ferromagnetic steels. Based on the examined volume of the sample, all methods used were divided into two large categories: the first one was related to the determination of surface residual stress, whereas the second one was related to bulk residual stress determination. The first category included the magnetic Barkhausen noise and the X-ray diffraction measurements, while the second one included the magnetic permeability and the neutron diffraction data. The residual stresses determined by the magnetic techniques were in a good agreement with the diffraction ones.

  7. Multi-Wave and Hybrid Imaging Techniques: A New Direction for Nondestructive Testing and Structural Health Monitoring

    PubMed Central

    Cheng, Yuhua; Deng, Yiming; Cao, Jing; Xiong, Xin; Bai, Libing; Li, Zhaojun

    2013-01-01

    In this article, the state-of-the-art multi-wave and hybrid imaging techniques in the field of nondestructive evaluation and structural health monitoring were comprehensively reviewed. A new direction for assessment and health monitoring of various structures by capitalizing the advantages of those imaging methods was discussed. Although sharing similar system configurations, the imaging physics and principles of multi-wave phenomena and hybrid imaging methods are inherently different. After a brief introduction of nondestructive evaluation (NDE), structure health monitoring (SHM) and their related challenges, several recent advances that have significantly extended imaging methods from laboratory development into practical applications were summarized, followed by conclusions and discussion on future directions. PMID:24287536

  8. The development of ultrasonic techniques for nondestructive evaluation of adhesive bonds

    NASA Astrophysics Data System (ADS)

    Chapman, Gilbert B., II

    Demands for improvements in aerospace and automotive energy-efficiency, performance, corrosion resistance, body stiffness and style have increased the use of adhesive bonds to help meet those demands by providing joining technology that accommodates a wider variety of materials and design options. However, the history of adhesive bond performance clearly indicates the need for a robust method of assuring the existence of the required consistent level of adhesive bond integrity in every bonded region. This investigation seeks to meet that need by the development of new, complementary ultrasonic techniques for the evaluation of these bonds, and thus provide improvements over previous methods by extending the range of resolution, speed and applications. The development of a 20 MHz pulse-echo method for nondestructive evaluation of adhesive bonds will accomplish the assessment of bond joints with adhesive as thin as 0.1 mm. This new method advances the state of the art by providing a high-resolution, phase-sensitive procedure that identifies the bond state at each interface of the adhesive with the substrate(s), by the acquisition and analysis of acoustic echoes reflected from interfaces between layers with large acoustic impedance mismatch. Because interface echo amplitudes are marginal when the acoustic impedance of the substrate is close to that of the adhesive, a 25 kHz Lamb wave technique was developed to be employed in such cases, albeit with reduced resolution. Modeling the ultrasonic echoes and Lamb-wave signals was accomplished using mathematical expressions developed from the physics of acoustic transmission, attenuation and reflection in layered media. The models were validated by experimental results from a variety of bond joint materials, geometries and conditions, thereby confirming the validity of the methodology used for extracting interpretations from the phase-sensitive indications, as well as identifying the range and limits of applications. Results

  9. Concept for Determining the Life of Ceramic Matrix Composites Using Nondestructive Characterization Techniques

    NASA Technical Reports Server (NTRS)

    Effinger, M.; Ellingson, B.; Spohnholtz, T.; Koenig, J.

    2001-01-01

    An idea is put forth for a nondestructive characterization (NDC) generated algorithm-N curve to replace a S-N curve. A scenario for NDC life determination has been proposed. There are many challenges for the NDC life determination and prediction, but it could yield a grand payoff. The justification for NDC life determination and prediction is documented.

  10. Saturn S-2 quality assurance techniques: Nondestructive testing processes. Volume 1: Requirements and procedures

    NASA Technical Reports Server (NTRS)

    Eller, H. H.; Sugg, F. E.

    1970-01-01

    The methods and procedures used to perform nondestructive testing inspections of the Saturn S-2 liquid hydrogen and liquid oxygen tank weldments during fabrication and after proof testing are described to document special skills developed during the program. All post-test inspection requirements are outlined including radiographic inspections procedures.

  11. Preliminary report of the comparison of multiple non-destructive assay techniques on LANL Plutonium Facility waste drums

    SciTech Connect

    Bonner, C.; Schanfein, M.; Estep, R.

    1999-03-01

    Prior to disposal, nuclear waste must be accurately characterized to identify and quantify the radioactive content. The DOE Complex faces the daunting task of measuring nuclear material with both a wide range of masses and matrices. Similarly daunting can be the selection of a non-destructive assay (NDA) technique(s) to efficiently perform the quantitative assay over the entire waste population. In fulfilling its role of a DOE Defense Programs nuclear User Facility/Technology Development Center, the Los Alamos National Laboratory Plutonium Facility recently tested three commercially built and owned, mobile nondestructive assay (NDA) systems with special nuclear materials (SNM). Two independent commercial companies financed the testing of their three mobile NDA systems at the site. Contained within a single trailer is Canberra Industries segmented gamma scanner/waste assay system (SGS/WAS) and neutron waste drum assay system (WDAS). The third system is a BNFL Instruments Inc. (formerly known as Pajarito Scientific Corporation) differential die-away imaging passive/active neutron (IPAN) counter. In an effort to increase the value of this comparison, additional NDA techniques at LANL were also used to measure these same drums. These are comprised of three tomographic gamma scanners (one mobile unit and two stationary) and one developmental differential die-away system. Although not certified standards, the authors hope that such a comparison will provide valuable data for those considering these different NDA techniques to measure their waste as well as the developers of the techniques.

  12. Comparison of destructive and nondestructive sampling techniques of retail chicken carcasses for enumeration of hygiene indicator microorganisms.

    PubMed

    Cossi, Marcus Vinícius Coutinho; de Almeida, Michelle Vieira; Dias, Mariane Rezende; de Arruda Pinto, Paulo Sérgiode; Nero, Luís Augusto

    2012-01-01

    The type of sampling technique used to obtain food samples is fundamental to the success of microbiological analysis. Destructive and nondestructive techniques, such as tissue excision and rinsing, respectively, are widely employed in obtaining samples from chicken carcasses. In this study, four sampling techniques used for chicken carcasses were compared to evaluate their performances in the enumeration of hygiene indicator microorganisms. Sixty fresh chicken carcasses were sampled by rinsing, tissue excision, superficial swabbing, and skin excision. All samples were submitted for enumeration of mesophilic aerobes, Enterobacteriaceae, coliforms, and Escherichia coli. The results were compared to determine the statistical significance of differences and correlation (P < 0.05). Tissue excision provided the highest microbial counts compared with the other procedures, with significant differences obtained only for coliforms and E. coli (P < 0.05). Significant correlations (P < 0.05) were observed for all the sampling techniques evaluated for most of the hygiene indicators. Despite presenting a higher recovery ability, tissue excision did not present significant differences for microorganism enumeration compared with other nondestructive techniques, such as rinsing, indicating its adequacy for microbiological analysis of chicken carcasses.

  13. A Survey of Shape Parameterization Techniques

    NASA Technical Reports Server (NTRS)

    Samareh, Jamshid A.

    1999-01-01

    This paper provides a survey of shape parameterization techniques for multidisciplinary optimization and highlights some emerging ideas. The survey focuses on the suitability of available techniques for complex configurations, with suitability criteria based on the efficiency, effectiveness, ease of implementation, and availability of analytical sensitivities for geometry and grids. The paper also contains a section on field grid regeneration, grid deformation, and sensitivity analysis techniques.

  14. An overview of the nondestructive inspection techniques for coiled tubing and pipe

    SciTech Connect

    Stanley, R.K.

    1996-11-01

    Coiled steel tubing and pipe in the diameter range 20--90 mm (0.75--3.5 in.) are replacing conventional oilfield materials for a variety of purposes including workovers, drilling, production tubing, umbilicals, and flowlines. They offer all the advantages of long tubes with no threaded connections. Because coiled tubing is being produced to high quality standards, it is lasting longer than ever before, and the need has arisen for careful nondestructive inspection at frequent intervals to determine accumulated damage to the string and the need for repair. Currently, derating of used coiled tubing using nondestructive testing (NDT) is not performed. While NDT devices for oilfield tubulars have been well documented, little has been written regarding the NDT of coiled tubing. This paper outlines the current NDT methods used during the manufacture of new tubing and the inspection of used coiled tubing.

  15. Depth resolved compositional analysis of aluminium oxide thin film using non-destructive soft x-ray reflectivity technique

    NASA Astrophysics Data System (ADS)

    Sinha, Mangalika; Modi, Mohammed H.

    2017-10-01

    In-depth compositional analysis of 240 Å thick aluminium oxide thin film has been carried out using soft x-ray reflectivity (SXR) and x-ray photoelectron spectroscopy technique (XPS). The compositional details of the film is estimated by modelling the optical index profile obtained from the SXR measurements over 60-200 Å wavelength region. The SXR measurements are carried out at Indus-1 reflectivity beamline. The method suggests that the principal film region is comprised of Al2O3 and AlOx (x = 1.6) phases whereas the interface region comprised of SiO2 and AlOx (x = 1.6) mixture. The soft x-ray reflectivity technique combined with XPS measurements explains the compositional details of principal layer. Since the interface region cannot be analyzed with the XPS technique in a non-destructive manner in such a case the SXR technique is a powerful tool for nondestructive compositional analysis of interface region.

  16. Survey of Biochemical Separation Techniques

    ERIC Educational Resources Information Center

    Nilsson, Melanie R.

    2007-01-01

    A simple laboratory exercise is illustrated that exposes students to wide range of separation techniques in one laboratory program and provides a nice complement to a project-oriented program. Students have learned the basic principles of syringe filtration, centricon, dialysis, gel filtration and solid-phase extraction methodologies and have got…

  17. Survey of Biochemical Separation Techniques

    ERIC Educational Resources Information Center

    Nilsson, Melanie R.

    2007-01-01

    A simple laboratory exercise is illustrated that exposes students to wide range of separation techniques in one laboratory program and provides a nice complement to a project-oriented program. Students have learned the basic principles of syringe filtration, centricon, dialysis, gel filtration and solid-phase extraction methodologies and have got…

  18. Survey of Header Compression Techniques

    NASA Technical Reports Server (NTRS)

    Ishac, Joseph

    2001-01-01

    This report provides a summary of several different header compression techniques. The different techniques included are: (1) Van Jacobson's header compression (RFC 1144); (2) SCPS (Space Communications Protocol Standards) header compression (SCPS-TP, SCPS-NP); (3) Robust header compression (ROHC); and (4) The header compression techniques in RFC2507 and RFC2508. The methodology for compression and error correction for these schemes are described in the remainder of this document. All of the header compression schemes support compression over simplex links, provided that the end receiver has some means of sending data back to the sender. However, if that return path does not exist, then neither Van Jacobson's nor SCPS can be used, since both rely on TCP (Transmission Control Protocol). In addition, under link conditions of low delay and low error, all of the schemes perform as expected. However, based on the methodology of the schemes, each scheme is likely to behave differently as conditions degrade. Van Jacobson's header compression relies heavily on the TCP retransmission timer and would suffer an increase in loss propagation should the link possess a high delay and/or bit error rate (BER). The SCPS header compression scheme protects against high delay environments by avoiding delta encoding between packets. Thus, loss propagation is avoided. However, SCPS is still affected by an increased BER (bit-error-rate) since the lack of delta encoding results in larger header sizes. Next, the schemes found in RFC2507 and RFC2508 perform well for non-TCP connections in poor conditions. RFC2507 performance with TCP connections is improved by various techniques over Van Jacobson's, but still suffers a performance hit with poor link properties. Also, RFC2507 offers the ability to send TCP data without delta encoding, similar to what SCPS offers. ROHC is similar to the previous two schemes, but adds additional CRCs (cyclic redundancy check) into headers and improves

  19. Nondestructive Testing Technique to Quantify Deterioration from Marine Borer Attack in Sitka Spruce and Western Hemlock Logs: Observations from a Pilot Test

    Treesearch

    Robert Ross; John W. Forsman; John R. Erickson; Allen M. Brackley

    2014-01-01

    Stress-wave nondestructive evaluation (NDE) techniques are used widely in the forest products industry—from the grading of wood veneer to inspection of timber structures. Inspection professionals frequently use stress-wave NDE techniques to locate internal voids and decayed or deteriorated areas in large timbers. Although these techniques have proven useful, little...

  20. Notched graphite polymimide composites at room and notched graphite polymide composites at room and elevated temperatures. [nondestructive test techniques

    NASA Technical Reports Server (NTRS)

    Awerbuch, J.; Perkinson, H. E.; Kamel, I. L.

    1980-01-01

    The fracture behavior in graphite/polyimide (Gr/PI) Celion 6000/PMR-15 composites was characterized. Emphasis was placed on the correlation between the observed failure modes and the deformation characteristics of center-notched Gr/Pl laminates. Crack tip damage growth, fracture strength and notch sensitivity, and the associated characterization methods were also examined. Special attention was given to nondestructive evaluation of internal damage and damage growth, techniques such as acoustic emission, X-ray radiography, and ultrasonic C-scan. Microstructural studies using scanning electron microscopy, photomicrography, and the pulsed nuclear magnetic resonance technique were employed as well. All experimental procedures and techniques are described and a summary of representative results for Gr/Pl laminates is given.

  1. Development of nondestructive testing techniques for plated-through holes in multilayer printed circuit boards

    NASA Technical Reports Server (NTRS)

    Anthony, P. L.; Mcmurtrey, J. E.

    1971-01-01

    The development of a nondestructive test with the capability to interrogate plated-through holes as small as 0.51 millimeters inside diameter is discussed. The system can detect defects such as holes, voids, cracks, and thin spots that reduce the current carrying capability of plates-through interconnects by 20 percent or more. Efforts were directed toward the design and fabrication of magnetic circuitry mutual coupling probes and to evaluate the effectiveness of these devices for detecting in multilayer board plated-through holes.

  2. Application of Advanced Nondestructive Evaluation Techniques for Cylindrical Composite Test Samples

    NASA Technical Reports Server (NTRS)

    Martin, Richard E.; Roth, Donald J.; Salem, Jonathan A.

    2013-01-01

    Two nondestructive methods were applied to composite cylinder samples pressurized to failure in order to determine manufacturing quality and monitor damage progression under load. A unique computed tomography (CT) image processing methodology developed at NASA Glenn Research was used to assess the condition of the as-received samples while acoustic emission (AE) monitoring was used to identify both the extent and location of damage within the samples up to failure. Results show the effectiveness of both of these methods in identifying potentially critical fabrication issues and their resulting impact on performance.

  3. Noncontact, nondestructive elasticity evaluation of sound and demineralized human dental enamel using a laser ultrasonic surface wave dispersion technique

    NASA Astrophysics Data System (ADS)

    Wang, Hsiao-Chuan; Fleming, Simon; Lee, Yung-Chun; Law, Susan; Swain, Michael; Xue, Jing

    2009-09-01

    Laser ultrasonic nondestructive evaluation (NDE) methods have been proposed to replace conventional in vivo dental clinical diagnosis tools that are either destructive or incapable of quantifying the elasticity of human dental enamel. In this work, a laser NDE system that can perform remote measurements on samples of small dimensions is presented. A focused laser line source is used to generate broadband surface acoustic wave impulses that are detected with a simplified optical fiber interferometer. The measured surface wave velocity dispersion spectrum is in turn used to characterize the elasticity of the specimen. The NDE system and the analysis technique are validated with measurements of different metal structures and then applied to evaluate human dental enamel. Artificial lesions are prepared on the samples to simulate different states of enamel elasticity. Measurement results for both sound and lesioned regions, as well as lesions of different severity, are clearly distinguishable from each other and fit well with physical expectations and theoretical value. This is the first time, to the best of our knowledge, that a laser-based surface wave velocity dispersion technique is successfully applied on human dental enamel, demonstrating the potential for noncontact, nondestructive in vivo detection of the development of carious lesions.

  4. Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage

    PubMed Central

    Mansour, Joseph M.; Lee, Zhenghong; Welter, Jean F.

    2016-01-01

    In this review, methods for evaluating the properties of tissue engineered (TE) cartilage are described. Many of these have been developed for evaluating properties of native and osteoarthritic articular cartilage. However, with the increasing interest in engineering cartilage, specialized methods are needed for nondestructive evaluation of tissue while it is developing and after it is implanted. Such methods are needed, in part, due to the large inter- and intra-donor variability in the performance of the cellular component of the tissue, which remains a barrier to delivering reliable TE cartilage for implantation. Using conventional destructive tests, such variability makes it near-impossible to predict the timing and outcome of the tissue engineering process at the level of a specific piece of engineered tissue and also makes it difficult to assess the impact of changing tissue engineering regimens. While it is clear that the true test of engineered cartilage is its performance after it is implanted, correlation of pre and post implantation properties determined non-destructively in vitro and/or in vivo with performance should lead to predictive methods to improve quality-control and to minimize the chances of implanting inferior tissue. PMID:26817458

  5. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    In this Progress Report, we describe our further development of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns transmitted through water only and transmitted through water and a thin woven composite. All images of diffraction patterns have been included on the accompanying CD-ROM in the JPEG format and Adobe TM Portable Document Format (PDF), in addition to the inclusion of hardcopies of the images contained in this report. In our previous semi-annual Progress Report (NAG 1-1848, December, 1996), we proposed a simple model to simulate the effect of a thin woven composite on an insonifying ultrasonic pressure field. This initial approach provided an avenue to begin development of a robust measurement method for nondestructive evaluation of anisotropic materials. In this Progress Report, we extend that work by performing experimental measurements on a single layer of a five-harness biaxial woven composite to investigate how a thin, yet architecturally complex, material interacts with the insonifying ultrasonic field. In Section 2 of this Progress Report we describe the experimental arrangement and methods for data acquisition of the ultrasonic diffraction patterns upon transmission through a thin woven composite. We also briefly describe the thin composite specimen investigated. Section 3 details the analysis of the experimental data followed by the experimental results in Section 4. Finally, a discussion of the observations and conclusions is found in Section 5.

  6. Feasibility on fiber orientation detection on unidirectional CFRP composite laminates using nondestructive evaluation techniques

    NASA Astrophysics Data System (ADS)

    Yang, In-Young; Kim, Ji-Hoon; Cha, Cheon-Seok; Lee, Kil-Sung; Hsu, David K.; Im, Kwang-Hee

    2007-07-01

    In particular, CFRP (carbon fiber reinforced plastics) composite materials have found wide applicability because of their inherent design flexibility and improved material properties. CFRP composites were manufactured from uni-direction prepreg sheet in this paper. It is important to assess fiber orientation, material properties and part defect in order to ensure product quality and structural integrity of CFRP because strength and stiffness of composites depend on fiber orientation. It is desirable to perform nondestructive evaluation which is very beneficial. An new method for nondestructively determining the fiber orientation in a composite laminate is presented. A one-sided pitch-catch setup was used in the detection and evaluation of flaws and material anomalies in the unidirectional CFRP composite laminates. Two Rayleigh wave transducers were joined head-to-head and used in the pitch-catch mode on the surface of the composites. The pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to subtle flaw conditions in the composite. Especially, ultrasonic waves were extensively characterized in the CFRP composite laminates both normal to fiber and along to fiber with using a one-sided direction of Rayleigh wave transducers. Also, one-sided ultrasonic measurement was made with using a Rayleigh wave transducers and a conventional scanner was used in an immersion tank for extracting fiber orientation information from the ultrasonic reflection in the unidirectional laminate. Therefore, it is thought that the proposed method is useful to evaluate integrity of CFRP laminates.

  7. Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage.

    PubMed

    Mansour, Joseph M; Lee, Zhenghong; Welter, Jean F

    2016-03-01

    In this review, methods for evaluating the properties of tissue engineered (TE) cartilage are described. Many of these have been developed for evaluating properties of native and osteoarthritic articular cartilage. However, with the increasing interest in engineering cartilage, specialized methods are needed for nondestructive evaluation of tissue while it is developing and after it is implanted. Such methods are needed, in part, due to the large inter- and intra-donor variability in the performance of the cellular component of the tissue, which remains a barrier to delivering reliable TE cartilage for implantation. Using conventional destructive tests, such variability makes it near-impossible to predict the timing and outcome of the tissue engineering process at the level of a specific piece of engineered tissue and also makes it difficult to assess the impact of changing tissue engineering regimens. While it is clear that the true test of engineered cartilage is its performance after it is implanted, correlation of pre and post implantation properties determined non-destructively in vitro and/or in vivo with performance should lead to predictive methods to improve quality-control and to minimize the chances of implanting inferior tissue.

  8. Survey of data compression techniques

    SciTech Connect

    Gryder, R.; Hake, K.

    1991-09-01

    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM`s design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  9. Survey of data compression techniques

    SciTech Connect

    Gryder, R.; Hake, K.

    1991-09-01

    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM's design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  10. Non-destructive analysis of didymium and praseodymium molybdate crystals using energy dispersive X-ray fluorescence technique

    NASA Astrophysics Data System (ADS)

    Bhat, C. K.; Joseph, Daisy; Pandita, Sanjay; Kotru, P. N.

    2016-08-01

    Analysis of didymium (Di) and praseodymium molybdate crystals were carried out using energy dispersive X-ray fluorescence (EDXRF). The assigned empirical chemical formulae of the composites were tested and verified by the EDXRF technique by estimating experimental major elemental concentration ratios. On the Basis of these ratios, the established formulae for some of the composite materials have been verified and suggestions made for their refinement. Non-destructive technique used in this analysis enables to retain the original crystal samples and makes rapid simultaneous scan of major elements such as La, Pr, Ned and Mo as well as impurities such as Ce. Absence of samarium(Sm) in the spectrum during analysis of didymium molybdate crystals indicated an incomplete growth of mixed rare earth single crystal. These crystals (e.g.,Di) are shown to be of modified stoichiometry with Ce as trace impurity.

  11. New measurement technique that uses three near infrared diode lasers for nondestructive evaluation of sugar content in fruits

    NASA Astrophysics Data System (ADS)

    Shimomura, Yoshiaki; Takami, Toshitaka; Ichimaru, Yoshiki; Matsuo, Kenichi; Hyodo, Ryuji

    2005-03-01

    For non-destructive evaluation of sugar content in fruits, it has been proposed new measurement technique that uses three near infrared diode lasers. The reflectance Ri at the wavelength λi is defined by the ratio of two diffuse light powers reaching the two receiving fibers that were positioned at the different distance from a light emitting fiber. The value γ = ln (Ri/Rk)/ln (Rj/Rk) reaches the value that doesn't approximately depend on optical path length. As a simulation result of γ to a modeled apple, it was found that there are some combinations of three near-infrared wavelengths in which the correlation of γ and the sugar content of fruits raise. We actually evaluated the sugar content of apples by the use of three diode lasers 911nm, 936nm and 1055nm. As a result, it was confirmed that the measurement technique proposed here was usefulness.

  12. Non-destructive and micro-invasive testing techniques for characterizing materials, structures and restoration problems in mural paintings

    NASA Astrophysics Data System (ADS)

    Tortora, Mariagrazia; Sfarra, Stefano; Chiarini, Marco; Daniele, Valeria; Taglieri, Giuliana; Cerichelli, Giorgio

    2016-11-01

    In this paper, chemical and structural studies of medieval wall paintings in Ocre (L'Aquila, Italy) are presented. During the latest restoration campaign, non-destructive (Near-Infrared Reflectography and Infrared Thermography) and micro-invasive (Nuclear Magnetic Resonance, Fourier Transform Infrared Spectroscopy, μ-Raman, Scanning Electron Microscopy with X-ray Microanalysis, X-Ray Diffraction, X-Ray Fluorescence, Optical Microscopy, Mass Spectrometry, Thermogravimetry) analyses were performed in order to determine the detachments of wall surfaces and the characterization of original and restoration materials. Data integration allowed to reconstruct the conservative history, the execution techniques and the conservation problems of the artefact, as well as to assess the effectiveness of restoration activities adopted. The combined use of physical and micro-chemical techniques proved to be effective for an in-depth study of materials stratification of paintings.

  13. Nondestructive measurement and analysis of residual stress in and around welds--A state of the art survey

    SciTech Connect

    Not Available

    1993-07-01

    One objective of mechanical design of welded fabrications is to compensate loads by stresses which the materials used in structural components can accommodate. Beside these load-induced stresses, residual stresses also have to be considered. These residual stresses are built up during weld pool cooling. All welded structures therefore have residual stresses, which can be relieved by heat treatment to below the yield-stress level at the annealing temperature. If not fully relieved, their presence can accelerate corrosion and corrosive cracking of welds. Quality assurance of welded structures needs tools for quantitative nondestructive analysis of stress states. The only nondestructive technique specifically developed for measurement and analysis of stress states is x-ray diffraction. Special devices for application under industrial or on-site environments have been developed and are extensively used. This type of measurement can be time-consuming, depending on the equipment, and has practical limitations. Moreover the penetration of x-rays into metals is small, in the order of 30 microns, and the measurements can be affected by other surface-related disturbance caused by machining and surface finishing. In the last ten years extensive research and development has been done to develop stress-analyzing techniques of a typical ndt-style,'' i.e., the use of a probe manipulated by hand or a manipulator, together with portable equipment. The present state of development of such an approach and the most important results obtained up to now are described in the following article.

  14. Detection of Secondary Phases in UNS S32760 Superduplex Stainless Steel by Destructive and Non-destructive Techniques

    NASA Astrophysics Data System (ADS)

    Argandona, G.; Biezma, M. V.; Berrueta, J. M.; Berlanga, C.; Ruiz, A.

    2016-12-01

    Duplex stainless steels (DSS), with a microstructure of an approximately equal mixture of ferrite ( α) and austenite ( γ) phases, are susceptible to the formation of undesirable phases if manufacturing processes are not carefully controlled. In particular, sigma phase (σ) is a Cr- and Mo-rich intermetallic phase, formed generally when DSS are by the temperature range from 600 to 900 °C, even for very short time periods. The precipitation of this phase induces detrimental effects in mechanical and corrosion resistance properties in the material, and even a low volume percentage of σ phase can significantly affect these properties. The current paper presents the effect of thermal treatments on UNS S32760 superduplex stainless steel seamless tubes, applied in order to promote the precipitation of different σ phase percentages in a ferrite/austenite microstructure. The detection and quantification of the σ phase using non-destructive ultrasounds testing has been one of the most relevant events of this study that contributes to improving the correlation of the results obtained using destructive and non-destructive techniques for the quantification of undesirable phases in superduplex seamless tubes during the manufacturing process.

  15. Flat nose low velocity drop-weight impact response of carbon fibre composites using non-destructive damage detection techniques

    NASA Astrophysics Data System (ADS)

    Farooq, Umar; Myler, Peter

    2015-03-01

    This work is mainly concerned with the nondestructive post-impact damage evaluation of carbon fibre reinforced laminated composite panels subject to low velocity drop-weight impact by flat and round nose impactors. Quasi-isotropic laminates consisting of eight-, sixteen-, and twenty-four plies were impacted by flat and round nose impactors at different velocity levels. Load-time history data were recorded and plotted to correlate loaddrop as damage level to the impactor nose profiles. Test produced data, non-destructive damage detection techniques: visual, ultrasonic, and eddy- current, and computer simulations were utilised to identify and quantify status of the impact induced damage. To evaluate damage in relatively thick laminates (consisting of 24-Ply), the damage ratios and deflection quantities were correlated to the corresponding impactor nose profiles. Damage induced by the flat nose impactor to thick laminates was compared against the data produced by the round nose impactor. Results show that relatively thin laminates were largely affected by the impactor nose. Reasonable difference was observed in damage caused by flat and round impactor nose profiles to thick laminates impacted at relatively higher velocity impacts. Resultswere compared and validated against simulation produced data.

  16. A portable nondestructive real-time detection system for inspection of pork quality attributes using Vis/NIR spectral technique

    NASA Astrophysics Data System (ADS)

    Sun, Hongwei; Peng, Yankun

    2016-05-01

    There are many preferences expressing the quality of pork: color, pH, especially TVB-N content. Different quality pork has different spectral feature (in range of 400 to 1000nm). To detect quality attributes of pork easily, real-time, nondestructively, a portable device based on Vis/NIR spectral technique was developed. The device is mainly made up of four units: light source, spectrometer, controller and display screen. After hardware platform established, reflectance spectra of 44 samples were collected from this system. And their physicochemical characteristics such as color parameters, pH value and the content of total volatile basic-nitrogen (TVB-N) were measured in standard methods. Spectrum data acquired were processed by Savitzky-Golay filter(S-G) for noise removal, and then operated by standard normal variable transformation (SNV) for baseline drifts relieving. The partial least squares regression (PLSR) was used to build prediction models for L*, a*, b* pH* and TVB-N content, which could gain good prediction results with Rp of 0.92, 0.91, 0.92, 0.95 and 0.96 respectively. The results demonstrated that this device could be a promising tool applied to detecting pork quality attributes portably, real-time and nondestructively.

  17. Nondestructive evaluation

    SciTech Connect

    Martz, H E

    1998-01-01

    The Nondestructive Evaluation (NDE) thrust area at Lawrence Livermore National Laboratory (LLNL) supports initiatives that advance inspection science and technology. The goal is to provide cutting-edge technologies, that show promise for quantitative inspection and characterization tools two to three years into the future. The NDE thrust area supports a multidisciplinary team, consisting of mechanical and electronics engineers, physicists, materials and computer scientists, chemists, technicians, and radiographers. These team members include personnel that cross departments within LLNL, and some are from academia and industry, within the US and abroad. This collaboration brings together the necessary and diver disciplines to provide the key scientific and technological advancements required to meet LLNL programmatic and industrial NDE challenges. The primary contributions of the NDE thrust area this year are described in these five reports: (1) Image Recovery Techniques for X-Ray Computed Tomography for Limited-Data Environments; (2) Techniques for Enhancing Laser Ultrasonic Nondestructive Evaluation; (3) Optical Inspection of Glass-Epoxy Bonds; (4) Miniature X-Ray Source Development; and (5) Improving Computed Tomography Design and Operation Using Simulation Tools.

  18. Monitoring beach changes using GPS surveying techniques

    USGS Publications Warehouse

    Morton, Robert; Leach, Mark P.; Paine, Jeffrey G.; Cardoza, Michael A.

    1993-01-01

    The adaptation of Global Positioning System (GPS) surveying techniques to beach monitoring activities is a promising response to this challenge. An experiment that employed both GPS and conventional beach surveying was conducted, and a new beach monitoring method employing kinematic GPS surveys was devised. This new method involves the collection of precise shore-parallel and shore-normal GPS positions from a moving vehicle so that an accurate two-dimensional beach surface can be generated. Results show that the GPS measurements agree with conventional shore-normal surveys at the 1 cm level, and repeated GPS measurements employing the moving vehicle demonstrate a precision of better than 1 cm. In addition, the nearly continuous sampling and increased resolution provided by the GPS surveying technique reveals alongshore changes in beach morphology that are undetected by conventional shore-normal profiles. The application of GPS surveying techniques combined with the refinement of appropriate methods for data collection and analysis provides a better understanding of beach changes, sediment transport, and storm impacts.

  19. Non-destructive techniques used during the restoration of the relief "Madonna and Child" by Jacopo Sansovino

    NASA Astrophysics Data System (ADS)

    Buccolieri, Alessandro; Buccolieri, Giovanni; Castellano, Alfredo; Colosso, Pietro Quarta; Miotto, Lidiana

    2015-08-01

    The characterization of the main pigments present in the papier-mâché relief depicting a " Madonna and Child" by Jacopo Sansovino, preserved at the National Museum of Fine Arts in Budapest, has been carried out using non-destructive techniques. In particular, an XRF portable instrument and an XRD apparatus were used in order to determine the elements and compounds of the pigments, respectively. The experimental results indicate that zinc and barium are present on the relief, and this demonstrates that the artwork has undergone restoration since zinc has been in use since 1840 AD. Moreover, radiographic and stereoradiographic analyses were performed several times in order to assess the condition of the work and, above all, the state of the boards that support the work, the cavity inside the cardboard, the surface and the presence of nails.

  20. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique

    PubMed Central

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G.; Alver, Ninel

    2015-01-01

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods. PMID:26251904

  1. Nondestructive evaluation of as-implanted and annealed ultra shallow junctions by photothermal and photoluminescence heterodyne techniques

    NASA Astrophysics Data System (ADS)

    Geiler, H. D.; Karge, H.; Wagner, M.; Lerch, W.; Paul, S.

    2005-08-01

    The control of implantation dose, ion energy and the junction depth after annealing are key points of the on-line metrology for ultra shallow junction fabrication. Nondestructive and non-contact optical methods are examined with respect to their applicability for related tasks. High sensitive low noise photothermal heterodyne (PTH) and photoluminescence heterodyne (PLH) techniques are applied to control implant parameters of 0.5 keV B+ - implants both immediately after implantation and after spike annealing. The photothermal response shows that beside dose and energy dependencies monitored after implantation the spike annealing results in a layer with reduced carrier lifetime and mobility. By photoluminescence response the existence of an impurity band and the correlation with the p-n-junction depth is demonstrated by measuring the response of carrier dynamics.

  2. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique.

    PubMed

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G; Alver, Ninel

    2015-08-05

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods.

  3. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    SciTech Connect

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P.

    1997-08-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today.

  4. Structural characterization of selective area growth GaN nanowires by non-destructive optical and electrical techniques

    NASA Astrophysics Data System (ADS)

    Secco, Eleonora; Minj, Albert; Garro, Núria; Cantarero, Andrés; Colchero, Jaime; Urban, Arne; Ivana Oppo, Carla; Malindretos, Joerg; Rizzi, Angela

    2015-08-01

    The growth selectivity and structural quality of GaN nanowires obtained by plasma-assisted molecular beam epitaxy on pre-patterned GaN(0001) templates are investigated by means of non-destructive techniques. Optimum control over the nanowire arrangement and size requires a pitch between the mask apertures below twice the diffusion length of Ga atoms. Lower pitches, however, seem to slightly diminish the structural quality of the material, as revealed by the increase of the Raman peak linewidths. The photoluminescence spectra of the nanowires show a considerable presence of basal plane stacking faults, whose density increases for decreasing nanowire diameter. The capabilities of Kelvin probe force microscopy for imaging these kind of defects are also demonstrated.

  5. Micro-compression: a novel technique for the nondestructive assessment of local bone failure.

    PubMed

    Müller, R; Gerber, S C; Hayes, W C

    1998-12-01

    Many bones within the axial and appendicular skeleton are subjected to repetitive, cyclic loading during the course of ordinary daily activities. If this repetitive loading is of sufficient magnitude or duration, fatigue failure of the bone tissue may result. In clinical orthopedics, trabecular fatigue fractures are observed as compressive stress fractures in the proximal femur, vertebrae, calcaneus and tibia, and are often preceded by buckling and bending of microstructural elements. However, the relative importance of bone density and architecture in the etiology of these fractures is poorly understood. The aim of the study was to investigate failure mechanisms of 3D trabecular bone using micro-computed tomography (microCT). Because of its nondestructive nature, microCT represents an ideal approach for performing not only static measurements of bone architecture but also dynamic measurements of failure initiation and propagation as well as damage accumulation. For the purpose of the study, a novel micro-compression device was devised to measure loaded trabecular bone specimens directly in a micro-tomographic system. The measurement window in the device was made of a radiolucent, highly stiff plastic to enable X-rays to penetrate the material. The micro-compressor has an outer diameter of 19 mm and a total length of 65 mm. The internal load chamber fits wet or dry bone specimens with maximal diameters of 9 mm and maximal lengths of 22 mm. For the actual measurement, first, the unloaded bone is measured in the microCT. Second, a load-displacement curve is recorded where the load is measured with an integrated mini-button load cell and the displacement is computed directly from the microCT scout-view. For each load case, a 3D snap-shot of the structure under load is taken providing 34 microm nominal resolution. Initial measurements included specimens from bovine tibiae and whale spine to investigate the influence of the structure type on the failure mechanism. In a

  6. [Nondestructive measurement of sugar content of Hami melon based on diffuse reflectance hyperspectral imaging technique].

    PubMed

    Ma, Ben-Xue; Xiao, Wen-Dong; Qi, Xiang-Xiang; He, Qing-Hai; Li, Feng-Xia

    2012-11-01

    The research on nondestructive test for detecting the sugar content of Hami melon by the technology of hyperspectral imaging was put forward. The research used the hyperspectral imaging system to get the diffuse reflective spectrum information (400 - 1 000 nm) of anilox class Hami melon sugar content, chose effective whole wavelength (500 - 820 nm)to do the modeling regression analysis the sugar content of Hami melon. The research compared the correction method of MSC and SNV, and also compared the influence of accuracy of modeling in terms of the spectrum pretreatment methods of original spectrum, first order differential, second order differential; Using the methods of PLS, SMLR and PCR, the comparative analysis of sugar content detection model effect with skin Hami melon and peel Hami melon was conducted. The results showed that after the original spectrum being processed by MSC and first order differential spectrum, modeling effect could be very good using the method of PLS and SMLR. Synthesizing correction set correlation coefficient and forecast modeling effect, it's feasible to detect the sugar content of skin Hami melon by the PLS method, with a correction sample correlation coefficient (R(c)) of 0.861 and the lower root mean square errors of correction (RMSEC) of 0.627, and a prediction sample correlation coefficient (R(p)) of 0.706 and root mean square errors of prediction (RMSEP) of 0.873. The best effect to detecti the sugar content of peel Hami melon was obtained by the SMLR method with a correction sample correlation coefficient (R(c)) of 0.928 and the lower root mean square errors of correction (RMSEC) of 0.458, with a Prediction sample correlation coefficient (R(p)) of 0.818 and root mean square errors of prediction (RMSEP) of 0.727. The results of this study indicate that the technology of hyperspectral imaging can be used to predict the sugar content of Hami melon.

  7. Integration of infrared and optical imaging techniques for the nondestructive inspection of aeronautic parts

    NASA Astrophysics Data System (ADS)

    López, F.; Sfarra, S.; Ibarra-Castanedo, C.; Paoletti, D.; Maldague, X.

    2015-05-01

    This work focuses in the implementation of infrared and optical imaging techniques for the inspection of aeronautics parts. To this aim, a helicopter blade with known defects is inspected with four different techniques: long pulse thermography, pulsed thermography, digital speckle photography (DSP) and holographic interferometry (HI). The first two techniques belongs to the group of infrared imaging techniques, which are based on the analysis of the infrared thermal patterns in order to detect internal anomalies in the material; whilst the last two (DSP and HI) corresponds to the optical imaging techniques which make use of visible light to measure the material response to an applied stress. Both techniques were applied using the active approach, i.e. an external stimulation is applied in order to produce a gradient in either, the thermal and/or displacement field of the material. The results are then compared in order to evaluate the advantages and limitations of each technique.

  8. Nondestructive evaluation/characterization of composite materials and structures using the acousto-ultrasonic techniques

    NASA Technical Reports Server (NTRS)

    Dos Reis, H. L. M.; Vary, A.

    1988-01-01

    This paper introduces the nature and the underlying rational of the acousto-ultrasonic stress wave factor technique and some of its applications to composite materials and structures. Furthermore, two examples of successful application of the acousto-ultrasonic technique are presented in detail. In the first example, the acousto-ultrasonic technique is used to evaluate the adhesive bond strength between rubber layers and steel plates, and in the seocnd example the tehcnique is used to monitor progressive damage in wire rope.

  9. A Review Study of Nondestructive Test Techniques for Residual Stresses in Aircraft Transparencies.

    DTIC Science & Technology

    1984-01-01

    ultrasonic technique TI based on the ultrasonic enerqly reflection at a liquid-solid interface maqneto-)hotoelsticity, and laser diffraction; .0) detailed...well trained enqineer; however, the possibilities of its use in the field environment exist. Ultrasonic technique II, based on enerqy reflection at a...Ultrasonic Velocity-Stress Relations and Third Order Elastic Constants 11 1.2.3.4 Ultrasonic Technique II: Reflection of Ultrasonic Enerqy at a Liquid-Solid

  10. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    In this Progress Report, we describe our recent developments of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns for a thin woven composite in an immersion setup. In addition, we compare apparent signal loss measurements of the thin woven composite for phase-sensitive and phase-insensitive detection methods. All images of diffraction patterns have been included on the accompanying CD-ROM in the Adobe(Trademark) Portable Document Format (PDF). Due to the extensive amount of data, however, hardcopies of only a small representative selection of the images are included within the printed report. This Progress Report presents experimental results that support successful implementation of single element as well as one and two-dimensional ultrasonic array technologies for the inspection of textile composite structures. In our previous reports, we have addressed issues regarding beam profiles of ultrasonic pressure fields transmitted through a water reference path and transmitted through a thin woven composite sample path. Furthermore, we presented experimental results of the effect of a thin woven composite on the magnitude of an insonifying ultrasonic pressure field. In addition to the study of ultrasonic beam profiles, we consider issues relevant to the application of single-element, one-dimensional, and two-dimensional array technologies towards probing the mechanical properties of advanced engineering composites and structures. We provide comparisons between phase-sensitive and phase-insensitive detection methods for determination of textile composite structure parameters. We also compare phase-sensitive and phase-insensitive - - ---- ----- apparent signal loss measurements in an effort to study the phenomenon of phase cancellation at the face of a finite-aperture single-element receiver. Furthermore, in this

  11. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    In this Progress Report, we describe our recent developments of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns for a thin woven composite in an immersion setup. In addition, we compare apparent signal loss measurements of the thin woven composite for phase-sensitive and phase-insensitive detection methods. All images of diffraction patterns have been included on the accompanying CD-ROM in the Adobe(Trademark) Portable Document Format (PDF). Due to the extensive amount of data, however, hardcopies of only a small representative selection of the images are included within the printed report. This Progress Report presents experimental results that support successful implementation of single element as well as one and two-dimensional ultrasonic array technologies for the inspection of textile composite structures. In our previous reports, we have addressed issues regarding beam profiles of ultrasonic pressure fields transmitted through a water reference path and transmitted through a thin woven composite sample path. Furthermore, we presented experimental results of the effect of a thin woven composite on the magnitude of an insonifying ultrasonic pressure field. In addition to the study of ultrasonic beam profiles, we consider issues relevant to the application of single-element, one-dimensional, and two-dimensional array technologies towards probing the mechanical properties of advanced engineering composites and structures. We provide comparisons between phase-sensitive and phase-insensitive detection methods for determination of textile composite structure parameters. We also compare phase-sensitive and phase-insensitive - - ---- ----- apparent signal loss measurements in an effort to study the phenomenon of phase cancellation at the face of a finite-aperture single-element receiver. Furthermore, in this

  12. Holocene Temperature Reconstructions from Arctic Lakes based on Alkenone Paleothermometry and Non-Destructive Scanning Techniques

    NASA Astrophysics Data System (ADS)

    D'Andrea, W. J.; Balascio, N. L.; Bradley, R. S.; Bakke, J.; Gjerde, M.; Kaufman, D. S.; Briner, J. P.; von Gunten, L.

    2014-12-01

    Generating continuous, accurate and quantitative Holocene temperature estimates from the Arctic is an ongoing challenge. In many Arctic regions, tree ring-based approaches cannot be used and lake sediments provide the most valuable repositories for extracting paleotemperature information. Advances in lacustrine alkenone paleothermometry now allow for quantitative reconstruction of lake-water temperature based on the UK37 values of sedimentary alkenones. In addition, a recent study demonstrated the efficacy of non-destructive scanning reflectance spectroscopy in the visible range (VIS-RS) for high-resolution quantitative temperature reconstruction from arctic lake sediments1. In this presentation, I will report a new UK37-based temperature reconstruction and a scanning VIS-RS record (using the RABD660;670 index as a measure of sedimentary chlorin content) from Kulusuk Lake in southeastern Greenland (65.6°N, 37.1°W). The UK37 record reveals a ~3°C increase in summer lake water temperatures between ~10ka and ~7ka followed by sustained warmth until ~4ka and a gradual (~3°C) cooling until ~400 yr BP. The strong correlation between UK37 and RABD660;670 measured in the same sediment core provides further evidence that in arctic lakes where temperature regulates primary productivity, and thereby sedimentary chlorin content, these proxies can be combined to develop high-resolution quantitative temperature records. The Holocene temperature history of Kulusuk Lake determined using this approach corresponds to changes in the size of the glaciers adjacent to the lake, as inferred from sediment minerogenic properties measured with scanning XRF. Glaciers retreated during early Holocene warming, likely disappeared during the period of mid-Holocene warmth, and advanced after 4ka. I will also discuss new UK37 and RABD660;670 reconstructions from northwestern Svalbard and the central Brooks Range of Alaska within the framework of published regional temperature reconstructions and

  13. A Survey of Techniques for Approximate Computing

    SciTech Connect

    Mittal, Sparsh

    2016-03-18

    Approximate computing trades off computation quality with the effort expended and as rising performance demands confront with plateauing resource budgets, approximate computing has become, not merely attractive, but even imperative. Here, we present a survey of techniques for approximate computing (AC). We discuss strategies for finding approximable program portions and monitoring output quality, techniques for using AC in different processing units (e.g., CPU, GPU and FPGA), processor components, memory technologies etc., and programming frameworks for AC. Moreover, we classify these techniques based on several key characteristics to emphasize their similarities and differences. Finally, the aim of this paper is to provide insights to researchers into working of AC techniques and inspire more efforts in this area to make AC the mainstream computing approach in future systems.

  14. A Survey of Techniques for Approximate Computing

    DOE PAGES

    Mittal, Sparsh

    2016-03-18

    Approximate computing trades off computation quality with the effort expended and as rising performance demands confront with plateauing resource budgets, approximate computing has become, not merely attractive, but even imperative. Here, we present a survey of techniques for approximate computing (AC). We discuss strategies for finding approximable program portions and monitoring output quality, techniques for using AC in different processing units (e.g., CPU, GPU and FPGA), processor components, memory technologies etc., and programming frameworks for AC. Moreover, we classify these techniques based on several key characteristics to emphasize their similarities and differences. Finally, the aim of this paper is tomore » provide insights to researchers into working of AC techniques and inspire more efforts in this area to make AC the mainstream computing approach in future systems.« less

  15. Advances in neutron radiographic techniques and applications: a method for nondestructive testing.

    PubMed

    Berger, Harold

    2004-10-01

    A brief history of neutron radiography is presented to set the stage for a discussion of significant neutron radiographic developments and an assessment of future directions for neutron radiography. Specific advances are seen in the use of modern, high dynamic range imaging methods (image plates and flat panels) and for high contrast techniques such as phase contrast, and phase-sensitive imaging. Competition for neutron radiographic inspection may develop as these techniques offer application prospects for X-ray methods.

  16. Development and optimization of thermographic techniques for Non-Destructive Evaluation of multilayered structures

    NASA Astrophysics Data System (ADS)

    Gavrilov, Dmitry J.

    Quality control of modern materials is of the utmost importance in science and industry. Methods for nondestructive evaluation of material properties and the presence of defects are numerous. They differ in terms of their sensitivity and applicability in various conditions, and they provide different kinds of data such as the speed of sound in the material, its hardness, radiation absorption, etc. Based on measured characteristics an analyst makes a decision on the material studied. This work addresses a class of methods known as active thermographic analysis. Thermography analyzes the temperature of the surface of the sample under different external conditions. By keeping track of temperature changes at the surface caused by a deposition of heat on the sample one can determine its material properties such as theand processing the data captured it is possible to make decisions on parameters of this sample. Among the data which can be acquired are such important information as the location of internal defects (e.g., detachments, hollows, inclusions), thickness of the material layers, thermal parameters of the material and the location of internal defects (e.g., detachments, hollows, inclusions). The first part of this research investigates a method for analysis of layered composite materials using the approach based on interference of so called temperature waves. As demonstrated using the expressions derived, one can determine the thermal properties of the layers of the sample by applying a harmonically modulated heat flux to the surfaces and measuring the phase of the periodically changing surface temperature. This approach can be of use in the field of designing and analysis of composite thermal insulation coatings. In the second part of this work a method of analyzing objects of fine art was investigated, particularly - detection of subsurface defects. In the process of preserving art it is of primary importance to determine whether restoration is necessary

  17. High-resolution spiral computed tomography with multiplanar reformatting, 3D surface- and volume rendering: a non-destructive method to visualize ancient Egyptian mummification techniques.

    PubMed

    Jansen, Roel J; Poulus, Martin; Taconis, Wijbren; Stoker, Jaap

    2002-01-01

    Ancient Egyptians used mummification techniques to prevent their deceased from decay. This study evaluates the potential of computed tomography (CT) in determining these techniques in a non-destructive way. Twenty-five mummies were studied by using high-resolution spiral CT, 1mm slice thickness for the head and 3mm slice thickness for the rest of the body. Images were reconstructed with 3D, multiplanar reformatting and volume rendering. In all cases the used mummification techniques could be reconstructed. The way the brain was removed, the presence of chemicals, like resin and natron, could be detected and the way the intestines were handled could be made visible. The use of CT is indispensable as a non-destructive method in the reconstruction of mummification techniques.

  18. Summary of nondestructive testing theory and practice

    NASA Technical Reports Server (NTRS)

    Meister, R. P.; Randall, M. D.; Mitchell, D. K.; Williams, L. P.; Pattee, H. E.

    1972-01-01

    The ability to fabricate design critical and man-rated aerospace structures using materials near the limits of their capabilities requires a comprehensive and dependable assurance program. The quality assurance program must rely heavily on nondestructive testing methods for thorough inspection to assess properties and quality of hardware items. A survey of nondestructive testing methods is presented to provide space program managers, supervisors and engineers who are unfamiliar with this technical area with appropriate insight into the commonly accepted nondestructive testing methods available, their interrelationships, used, advantages and limitations. Primary emphasis is placed on the most common methods: liquid penetrant, magnetic particle, radiography, ultrasonics and eddy current. A number of the newer test techniques including thermal, acoustic emission, holography, microwaves, eddy-sonic and exo-electron emission, which are beginning to be used in applications of interest to NASA, are also discussed briefly.

  19. Digital Recording and Non-Destructive Techniques for the Understanding of Structural Performance for Rehabilitating Historic Structures at the Kathmandu Valley after Gorkha Earthquake 2015

    NASA Astrophysics Data System (ADS)

    Shrestha, S.; Reina Ortiz, M.; Gutland, M.; Napolitano, R.; Morris, I. M.; Santana Quintero, M.; Erochko, J.; Kawan, S.; Shrestha, R. G.; Awal, P.; Suwal, S.; Duwal, S.; Maharjan, D. K.

    2017-08-01

    On 25 April 2015, the Gorkha earthquake of magnitude 7.8, severely damaged the cultural heritage sites of Nepal. In particular, the seven monument zones of the Kathmandu Valley World Heritage Site suffered extensive damage. Out of 195 surveyed monuments, 38 have completely collapsed and 157 partially damaged (DoA, 2015). In particular, the world historic city of Bhaktapur was heavily affected by the earthquake. There is, in general, a lack of knowledge regarding the traditional construction technology used in many of the most important temple monuments in Bhaktapur. To address this limitation and to assist in reconstruction and rehabilitation of the area, this study documents the existing condition of different historic structures in the Kathmandu Valley. In particular, the Nyatapola Temple is studied in detail. To record and document the condition of this temple, a combination of laser scanning and terrestrial and aerial photogrammetry are used. By also including evaluation of the temple and its supporting plinth structure using non-destructive evaluation techniques like geo-radar and micro-tremor dynamic analysis, this study will form the basis of a structural analysis study to assess the anticipated future seismic performance of the Nyatapola Temple.

  20. A feasibility and optimization study to determine cooling time and burnup of advanced test reactor fuels using a nondestructive technique

    SciTech Connect

    Navarro, Jorge

    2013-12-01

    The goal of this study presented is to determine the best available non-destructive technique necessary to collect validation data as well as to determine burn-up and cooling time of the fuel elements onsite at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads3 to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements non-destructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed was used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however in order to enhance the quality of the spectra collected using this scintillator a deconvolution method was developed. Following the development of the deconvolution method

  1. Non-Destructive and rapid evaluation of staple foods quality by using spectroscopic techniques: A review.

    PubMed

    Su, Wen-Hao; He, Hong-Ju; Sun, Da-Wen

    2017-03-24

    Staple foods, including cereals, legumes, and root/tuber crops, dominate the daily diet of humans by providing valuable proteins, starch, oils, minerals, and vitamins. Quality evaluation of staple foods is primarily carried out on sensory (e.g. external defect, color), adulteration (e.g. species, origin), chemical (e.g. starch, proteins), mycotoxin (e.g. Fusarium toxin, aflatoxin), parasitic infection (e.g. weevil, beetle), and internal physiological (e.g. hollow heart, black heart) aspects. Conventional methods for the quality assessment of staple foods are always laborious, destructive, and time-consuming. Requirements for online monitoring of staple foods have been proposed to encourage the development of rapid, reagentless, and noninvasive techniques. Spectroscopic techniques, such as visible-infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance spectroscopy, and spectral imaging, have been introduced as promising analytical tools and applied for the quality evaluation of staple foods. This review summarizes the recent applications and progress of such spectroscopic techniques in determining various qualities of staple foods. Besides, challenges and future trends of these spectroscopic techniques are also presented.

  2. Application of ultrasonic technique in nondestructive food quality analysis: a review

    USDA-ARS?s Scientific Manuscript database

    Quality control and safe storage is important in food processing and storage. Composition of food has more effect on quality in terms of nutritional values, functional properties, commercial values and storage conditions of the food products. Traditional analytical techniques that are used for compo...

  3. Mantle biopsy: a technique for nondestructive tissue-sampling of freshwater mussels

    Treesearch

    David J. Berg; Wendell R. Haag; Sheldon I. Guttman; James B. Sickel

    1995-01-01

    Mantle biopsy is a means of obtaining tissue samples for genetic, physiological, and contaminant studies of bivalves; but the effects of this biopsy on survival have not been determined. We describe a simple technique for obtaining such samples from unionacean bivalves and how we compared survival among biopsied and control organisms in field experiments. Survival was...

  4. Nondestructive FT-IR Sampling Technique to Study Glass Fiber Composite Interfaces.

    DTIC Science & Technology

    1983-06-20

    powder was used as the refer- ence material so that the Kubelka - Munk reflectance plot could be produced. The sample was ratioed against the KBr...flectance technique is based on scattering of light by the sample which is collected and analyzed by the Kubelka - Munk theory and yields a reflectance

  5. Non-destructive evaluation techniques, high temperature ceramic component parts for gas turbines

    NASA Technical Reports Server (NTRS)

    Reiter, H.; Hirsekorn, S.; Lottermoser, J.; Goebbels, K.

    1984-01-01

    This report concerns studies conducted on various tests undertaken on material without destroying the material. Tests included: microradiographic techniques, vibration analysis, high-frequency ultrasonic tests with the addition of evaluation of defects and structure through analysis of ultrasonic scattering data, microwave tests and analysis of sound emission.

  6. Nondestructive evaluation of neutron irradiation embrittlement for reactor vessel steel by magnetomechanical acoustic emission technique

    SciTech Connect

    Maeda, Noriyoshi; Yamaguchi, Atsunori; Saito, Kiyoshi; Hirasawa, Taiji; Komura, Ichiroh; Chujou, Noriyuki

    1999-10-01

    A modified magnetomechanical acoustic emission (MAE) technique denoted Pulse MAE, in which the magnetizing current has a rectangular wave form, was developed as an NDE technique. Its applicability to the radiation damage for reactor pressure vessel steel was evaluated. The reactor pressure vessel steel A533B base metal and weld metal were irradiated to the two fluence levels: 5 {times} 10{sup 22} and 3 {times} 10{sup 23} n/m{sup 2} at 288 C. One side of the specimen was electropolished after irradiation. Pulse MAE signals were measured with a 350 kHz resonance frequency AE sensor at the moment when the magnetizing voltage is applied from zero to the set-up value abruptly. The AE signals were analyzed and the peak voltage Vp was determined for the measuring parameter. The peak voltage Vp showed the tendency to increase monotonically with increasing neutron fluence. The relationship between the Vp and mechanical properties such as yield stress, tensile strength and Charpy transition temperature were also obtained. The Pulse MAE technique proved to have the possibility to detect and evaluate the neutron irradiation embrittlement. The potential of the Pulse MAE as an effective NDE technique and applicability to the actual components are discussed.

  7. Real-time nondestructive testing of composite aeronautical structures with a self-adaptive ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Robert, S.; Casula, O.; Roy, O.; Neau, G.

    2013-07-01

    In the aeronautical industry, composite structures under testing often have complex and variable geometries. In such cases, an optimal use of ultrasonic transducer arrays requires specific algorithms in electronic systems in order to achieve rapid and reliable inspections. To fulfil such requirements, a new real-time and adaptive technique is presented. The surface adaptive ultrasound (SAUL) technique is based on an iterative algorithm that does not require a prior knowledge of the geometrical properties of the inspected domain. All different parts of a given component can be controlled using the same transducer array, such as a conventional linear array with a flat shape. In this paper, the adaptive processing is demonstrated through acquisitions performed with different typical aircraft composite structures. In addition, we present a new surface reconstruction algorithm. This fast algorithm is efficient and can be coupled with the real-time adaptive processing to reconstruct SAUL images and, then, to improve the characterization of flaws in composite materials.

  8. Sensing Applied Load and Damage Effects in Composites with Nondestructive Techniques

    DTIC Science & Technology

    2017-05-01

    and correlated . This report summarizes experimental setups involving the various NDE methods and technics and provide results on the effects of load... Correlating and validating NDE strategies for sensing damage and operational effects on composite materials will add to the knowledge of composites and...multiple NDE Approved for public release; distribution is unlimited. 5 techniques are used in this study for mutual correlation and verification

  9. Development of nondestructive crack inspection technique for conveyance roll using vibro-thermography

    NASA Astrophysics Data System (ADS)

    Imanishi, Daisuke; Nishina, Yoshiaki; Yoshinaga, Youichi

    2012-06-01

    In recent study, active thermography has reached a high status as an easy and speedy defects inspection method in a NDT field. This paper newly proposes a non-disassembly and non-contact NDT method using the Vibro-Thermography for detecting and evaluating of fatigue cracks at neck parts of the conveyance roll in the steel making plant. In this method, fatigue cracks are detected as localized high temperature areas caused by friction and impact at crack surfaces with an infrared thermography, applying a high-amplitude ultrasonic vibration. In the case of the roll surface is covered with lubricating grease or dust, the crack detectability is shown. Self reference lock-in data processing technique is applied for improvement of signal noise ratio in the crack detection process. This technique makes it possible to perform correlating process without an external reference signal. Time and cost saving inspection method in the neck part of conveyance roll is carried out using this NDT technique.

  10. Effective combination of DIC, AE, and UPV nondestructive techniques on a scaled model of the Belgian nuclear waste container

    NASA Astrophysics Data System (ADS)

    Iliopoulos, Sokratis N.; Areias, Lou; Pyl, Lincy; Vantomme, John; Van Marcke, Philippe; Coppens, Erik; Aggelis, Dimitrios G.

    2015-03-01

    Protecting the environment and future generations against the potential hazards arising from high-level and heat emitting radioactive waste is a worldwide concern. Following this direction, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials has come up with the reference design which considers the geological disposal of the waste in purely indurated clay. In this design the wastes are first post-conditioned in massive concrete structures called Supercontainers before being transported to the underground repositories. The Supercontainers are cylindrical structures which consist of four engineering barriers that from the inner to the outer surface are namely: the overpack, the filler, the concrete buffer and possibly the envelope. The overpack, which is made of carbon steel, is the place where the vitrified wastes and spent fuel are stored. The buffer, which is made of concrete, creates a highly alkaline environment ensuring slow and uniform overpack corrosion as well as radiological shielding. In order to evaluate the feasibility to construct such Supercontainers two scaled models have so far been designed and tested. The first scaled model indicated crack formation on the surface of the concrete buffer but the absence of a crack detection and monitoring system precluded defining the exact time of crack initiation, as well as the origin, the penetration depth, the crack path and the propagation history. For this reason, the second scaled model test was performed to obtain further insight by answering to the aforementioned questions using the Digital Image Correlation, Acoustic Emission and Ultrasonic Pulse Velocity nondestructive testing techniques.

  11. Interfacial Aspects of Electrodeposited Conductive Fibers/Epoxy Composites using Electro-Micromechanical Technique and Nondestructive Evaluation.

    PubMed

    Park, Joung-Man; Lee, Sang-Il; Kim, Ki-Won; Yoon, Dong-Jin

    2001-05-01

    Interfacial adhesion and nondestructive behavior of the electrodeposited (ED) carbon fiber reinforced composites were evaluated using the electro-micromechanical technique and acoustic emission (AE). Interfacial shear strength (IFSS) of the ED carbon fiber/epoxy composites was higher than that of the untreated case. This might be expected because of the possible chemical and hydrogen bonding based on an electrically adsorbed polymeric interlayer. Logarithmic electrical resistivity of the untreated single-carbon fiber composite increased suddenly to infinity when the fiber fracture occurred, whereas that of the ED composite increased relatively broadly up to infinity. This may be due to the retarded fracture time as a result of the enhanced IFSS. In single- and 10-carbon fiber composites, the number of AE signals coming from the interlayer failure of the ED carbon fiber composite was much larger than that of the untreated composite. As the number of each first fiber fracture increased in the 10-carbon fiber composite, the electrical resistivity increased stepwise, and the slope of logarithmic electrical resistance increased. In the three-graphite filament composite with a narrow 1 time inter-filament distance, the total numbers of the filament fracture and the IFSS were smaller than those of the wider 5 times case. This might be because the interacting fracture energy caused by a filament break could affect the adjacent filaments. Copyright 2001 Academic Press.

  12. Inspection of the Space Shuttle External Tank SOFI Using Near-Field and Focused Millimeter Wave Nondestructive Testing Techniques

    NASA Technical Reports Server (NTRS)

    Kharkovsky, S.; Hepburn, F.; Walker, J.; Zoughi, R.

    2005-01-01

    The Space Shuttle Columbia's catastrophic failure has been attributed to a piece of external tank SOFI (Spray On Foam Insulation) striking the left wing of the orbiter causing significant damage to some of the reinforced carbon/carbon leading edge wing panels. Subsequently, several nondestructive testing (NDT) techniques have been considered for inspecting the external tank. One such method involves using millimeter waves which have been shown to easily penetrate through the foam and provide high resolution images of its interior structures. This paper presents the results of inspecting three different SOFI covered panels by reflectometers at millimeter wave frequencies, specifically at 100 GHz. Each panel was fitted with various embedded anomalies/inserts representing voids and unbonds of diferent shapes, sizes and locations within each panel. In conjunction with these reJqectome&rs, radiators including a focused lens antenna and a small horn antenna were used. The focused lens antenna provided for a footprint diameter of approximately 1.25 cm (0.5") at 25.4 cm (10") away from the lens surface. The horn antenna was primarily operated in its near-field for obtaining relatively high resolution images. These images were produced using 2 0 scanning mechanisms. Discussions of the difference between the capabilities of these two types of antennas (radiators) for the purpose of inspecting the SOFI as it relates to the produced images are also presented.

  13. Photon-based techniques for nondestructive subsurface analysis of painted cultural heritage artifacts.

    PubMed

    Janssens, K; Dik, J; Cotte, M; Susini, J

    2010-06-15

    Often, just micrometers below a painting's surface lies a wealth of information, both with Old Masters such as Peter Paul Rubens and Rembrandt van Rijn and with more recent artists of great renown such as Vincent Van Gogh and James Ensor. Subsurface layers may include underdrawing, underpainting, and alterations, and in a growing number of cases conservators have discovered abandoned compositions on paintings, illustrating artists' practice of reusing a canvas or panel. The standard methods for studying the inner structure of cultural heritage (CH) artifacts are infrared reflectography and X-ray radiography, techniques that are optionally complemented with the microscopic analysis of cross-sectioned samples. These methods have limitations, but recently, a number of fundamentally new approaches for fully imaging the buildup of hidden paint layers and other complex three-dimensional (3D) substructures have been put into practice. In this Account, we discuss these developments and their recent practical application with CH artifacts. We begin with a tabular summary of 14 IR- and X-ray-based imaging methods and then continue with a discussion of each technique, illustrating CH applications with specific case studies. X-ray-based tomographic and laminographic techniques can be used to generate 3D renditions of artifacts of varying dimensions. These methods are proving invaluable for exploring inner structures, identifying the conservation state, and postulating the original manufacturing technology of metallic and other sculptures. In the analysis of paint layers, terahertz time-domain spectroscopy (THz-TDS) can highlight interfaces between layers in a stratigraphic buildup, whereas macrosopic scanning X-ray fluorescence (MA-XRF) has been employed to measure the distribution of pigments within these layers. This combination of innovative methods provides topographic and color information about the micrometer depth scale, allowing us to look "into" paintings in an

  14. Nondestructive determination of plutonium mass in spent fuel: prelliminary modeling results using the passive neutron Albedo reactivity technique

    SciTech Connect

    Evans, Louise G; Tobin, Stephen J; Schear, Melissa A; Menlove, Howard O; Lee, Sang Y; Swinhoe, Martyn T

    2009-01-01

    There are a variety of motivations for quantifying plutonium (Pu) in spent fuel assemblies by means of nondestructive assay (NDA) including the following: strengthening the capability of the International Atomic Energy Agency (LAEA) to safeguard nuclear facilities, quantifying shipper/receiver difference, determining the input accountability value at pyrochemical processing facilities, providing quantitative input to burnup credit and final safeguards measurements at a long-term repository. In order to determine Pu mass in spent fuel assemblies, thirteen NDA techniques were identified that provide information about the composition of an assembly. A key motivation of the present research is the realization that none of these techniques, in isolation, is capable of both (1) quantifying the Pu mass of an assembly and (2) detecting the diversion of a significant number of rods. It is therefore anticipated that a combination of techniques will be required. A 5 year effort funded by the Next Generation Safeguards Initiative (NGSI) of the U.S. DOE was recently started in pursuit of these goals. The first two years involves researching all thirteen techniques using Monte Carlo modeling while the final three years involves fabricating hardware and measuring spent fuel. Here, we present the work in two main parts: (1) an overview of this NGSI effort describing the motivations and approach being taken; (2) The preliminary results for one of the NDA techniques - Passive Neutron Albedo Reactivity (PNAR). The PNAR technique functions by using the intrinsic neutron emission of the fuel (primarily from the spontaneous fission of curium) to self-interrogate any fissile material present. Two separate measurements of the spent fuel are made, both with and without cadmium (Cd) present. The ratios of the Singles, Doubles and Triples count rates obtained in each case are analyzed; known as the Cd ratio. The primary differences between the two measurements are the neutron energy spectrum

  15. Gpr and Seismic Based Non-Destructive Geophysical Survey for Reinforcement of Historical Fire Tower of Sopron-Hungary

    NASA Astrophysics Data System (ADS)

    Kanli, A. I.; Taller, G.; Nagy, P.; Tildy, P.; Pronay, Z.; Toros, E.

    2013-12-01

    The Fire-Tower which is located in the main square at the hearth of Sopron is the symbol of the city. The museum of Sopron exists in the Storno-house west from the tower. The new city hall stands next to the tower to the east. Funds are from the roman age while the tower was first mentioned in writing in 1409. In 1676, it was burned down to the ground, but re-constructed. In 1894, the old City Hall was deconstucted, but the tower became unstable. István Kiss and Frigyes Schulek saved it by the walling up of the gate. In the year 1928, the scuptures of the main gate which symbolizes the fidelity of the town was sculpted by Zsigmond Kisfaludy Strobl. The old building was deconstructed from its west side, a new concrate museum was built in 1970. After years, important renovation and reinforcement studies had to be needed. For this aim, during the renovation and reinforcement studies, GPR and Seismic based non-destructive geophysical surveys were carried out before and after cement injection to observe the changes of the wall conditions of the historical tower located in Sopron-Hungary for understanding the success of the reinforcements studies. In the GPR survey, 400 MHz and 900 MHz antennas were used. The space between each profiles were taken as 0.5 m for 400 MHz and 0.25m for 900 MHz respectively. After the injection process, reflections from the fractured and porous zones were weakened imaged clearly by GPR data and significant rise of the p-wave velocities were observed.

  16. Nonlinear imaging techniques as non-destructive, high-resolution diagnostic tools for cultural heritage studies

    NASA Astrophysics Data System (ADS)

    Filippidis, G.; Tserevelakis, G. J.; Selimis, A.; Fotakis, C.

    2015-02-01

    Here, we present a review of the implementation of nonlinear imaging microscopy techniques such as second and third harmonic generation (SHG-THG) and multi-photon excitation fluorescence (MPEF), as high-resolution, non-invasive diagnostic tools for cultural heritage studies. Specifically, the above nonlinear modalities are employed for the precise three-dimensional (3D) delineation of the protective layers bulk in model multilayer painting artworks. The high axial resolution thickness determination of protective layers through the use of THG imaging and the identification of the chemical composition of the artefacts via MPEF measurements are depicted. Furthermore, we reveal the potential of MPEF imaging measurements for the identification of the corrosion layers in silver-based artefacts. Finally, nonlinear modalities are employed for the assessment of the affected region and the obtainment of depth information during laser cleaning of polymeric coatings.

  17. Noise measurements in thin-film interconnections: A nondestructive technique to characterize electromigration

    NASA Astrophysics Data System (ADS)

    Bagnoli, P. E.; Diligenti, A.; Neri, B.; Ciucci, S.

    1988-03-01

    Electromigration in aluminum and aluminum-silicon (1%) resistors was detected by means of a new technique based on the particular features of an ultralow-noise amplifier, which made it possible to evaluate the stochastic resistance fluctuations associated with vacancy generation-recombination processes. The power spectra of these fluctuations display a 1/f γ behavior with 2≤γ≤2.6, in the frequency range 10 mHz-1 Hz, and the analysis of these spectra, recorded at various current densities and temperatures, led to an evaluation of the activation energies characteristic of the process. Scanning electron microscope observation of the damage induced by stressing the resistors at the same current density and temperature as the spectra measurement but for a longer time, showed that what was being observed was the electromigration phenomenon in its early stages.

  18. Determining plutonium mass in spent fuel with non-destructive assay techniques - NGSU research overview and update on 6 NDA techniques

    SciTech Connect

    Tobin, Stephen J; Conlin, Jeremy L; Evans, Louise G; Hu, Jianwei; Blanc, Pauline C; Lafleur, Adrienne M; Menlove, Howard O; Schear, Melissa A; Swinhoe, Martyn T; Croft, Stephen; Fensin, Michael L; Freeman, Corey R; Koehler, William E; Mozin, V; Sandoval, N P; Lee, T H; Cambell, L W; Cheatham, J R; Gesh, C J; Hunt, A; Ludewigt, B A; Smith, L E; Sterbentz, J

    2010-09-15

    This poster is one of two complementary posters. The Next Generation Safeguards Initiative (NGSI) of the U.S. DOE has initiated a multi-lab/university collaboration to quantify the plutonium (Pu) mass in, and detect the diversion of pins from, spent nuclear fuel assemblies with non-destructive assay (NDA). This research effort has the goal of quantifying the capability of 14 NDA techniques as well as training a future generation of safeguards practitioners. By November of 2010, we will be 1.5 years into the first phase (2.5 years) of work. This first phase involves primarily Monte Carlo modelling while the second phase (also 2.5 years) will focus on experimental work. The goal of phase one is to quantify the detection capability of the various techniques for the benefit of safeguard technology developers, regulators, and policy makers as well as to determine what integrated techniques merit experimental work, We are considering a wide range of possible technologies since our research horizon is longer term than the focus of most regulator bodies. The capability of all of the NDA techniques will be determined for a library of 64 17 x 17 PWR assemblies [burnups (15, 30, 45, 60 GWd/tU), initial enrichments (2, 3, 4, 5%) and cooling times (1, 5, 20, 80 years)]. The burnup and cooling time were simulated with each fuel pin being comprised of four radial regions. In this paper an overview of the purpose will be given as well as a technical update on the following 6 neutron techniques: {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Passive Neutron Albedo Reactivity, Self-Integration Neutron Resonance Densitometry. The technical update will quantify the anticipated performance of each technique for the 64 assemblies of the spent fuel library.

  19. Advanced Non-Destructive Ocular Visualization Methods by Improved X-Ray Imaging Techniques.

    PubMed

    Enders, Christian; Braig, Eva-Maria; Scherer, Kai; Werner, Jens U; Lang, Gerhard K; Lang, Gabriele E; Pfeiffer, Franz; Noël, Peter; Rummeny, Ernst; Herzen, Julia

    2017-01-01

    Due to limited X-ray contrast, the use of micro-CT in histology is so far not as widespread as predicted. While specific staining procedures-mostly using iodine-address this shortcoming, long diffusion times restrict its use in the often time-constrained daily routine. Recently, a novel staining protocol has been proposed using a biochemical preconditioning step, which increases the permeability of the cells for the staining agent. This could enable the imaging of entire organs of small mammals at a yet unmatched image quality with reasonable preparation and scan times. We here propose an adaptation of this technique for virtual ophthalmology and histology by volumetrically assessing both human and porcine eyes. Hereby, we demonstrate that (contrast-enhanced) micro-CT can outperform conventional histology in the assessment of tumor entities, as well as functioning as a supplementary tool for surgeons in the positioning of intraocular implants in-vitro and as a general assessment tool for ophthalmologic specimens.

  20. Advanced Non-Destructive Ocular Visualization Methods by Improved X-Ray Imaging Techniques

    PubMed Central

    Scherer, Kai; Werner, Jens U.; Lang, Gerhard K.; Lang, Gabriele E.; Pfeiffer, Franz; Noël, Peter; Rummeny, Ernst; Herzen, Julia

    2017-01-01

    Due to limited X-ray contrast, the use of micro-CT in histology is so far not as widespread as predicted. While specific staining procedures—mostly using iodine—address this shortcoming, long diffusion times restrict its use in the often time-constrained daily routine. Recently, a novel staining protocol has been proposed using a biochemical preconditioning step, which increases the permeability of the cells for the staining agent. This could enable the imaging of entire organs of small mammals at a yet unmatched image quality with reasonable preparation and scan times. We here propose an adaptation of this technique for virtual ophthalmology and histology by volumetrically assessing both human and porcine eyes. Hereby, we demonstrate that (contrast-enhanced) micro-CT can outperform conventional histology in the assessment of tumor entities, as well as functioning as a supplementary tool for surgeons in the positioning of intraocular implants in-vitro and as a general assessment tool for ophthalmologic specimens. PMID:28129364

  1. X-ray computed tomography imaging: A not-so-nondestructive technique

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.; Sears, Hazel; Ebel, Denton S.; Wallace, Sean; Friedrich, Jon M.

    2016-04-01

    X-ray computed tomography has become a popular means for examining the interiors of meteorites and has been advocated for routine curation and for the examination of samples returned by missions. Here, we report the results of a blind test that indicate that CT imaging deposits a considerable radiation dose in a meteorite and seriously compromises its natural radiation record. Ten vials of the Bruderheim L6 chondrite were placed in CT imager and exposed to radiation levels typical for meteorite studies. Half were retained as controls. Their thermoluminescence (TL) properties were then measured in a blind test. Five of the samples had TL data unaltered from their original (~10 cps) while five had very strong signals (~20,000 cps). It was therefore very clear which samples had been in the CT scanner. For comparison, the natural TL signal from Antarctic meteorites is ~5000-50,000 cps. Using the methods developed for Antarctic meteorites, the apparent dose absorbed by the five test samples was calculated to be 83 ± 5 krad, comparable with the highest doses observed in Antarctic meteorites and freshly fallen meteorites. While these results do not preclude the use of CT scanners when scientifically justified, it should be remembered that the record of radiation exposure to ionizing radiations for the sample will be destroyed and that TL, or the related optically stimulated luminescence, are the primary modern techniques for radiation dosimetry. This is particularly important with irreplaceable samples, such as meteorite main masses, returned samples, and samples destined for archive.

  2. Non-destructive Detection of Small Blowholes in Aluminum by Using Laser Ultrasonics Technique

    NASA Astrophysics Data System (ADS)

    Sun, Kaihua; Shen, Zhonghua; Shi, Yifei; Xu, Zhihong; Yuan, Ling; Ni, Xiaowu

    2015-06-01

    In this paper, blowhole defects of sub-millimeter diameter in an aluminum alloy are successfully detected by the laser ultrasonic (LU) technique. A Q-switched and pulsed Nd:YAG laser is used for ultrasonic generation, and a laser Doppler vibration meter is used for detection of ultrasound waves on the sample surface. Through adding a thin and transparent film on the sample, a bulk wave penetrating method can be used for evaluating the position and size of the blowhole defects using the LU system. And the directivities of a longitudinal wave generated by a laser at different conditions are discussed. By two-dimensional moving of the sample with a precise motorized translation platform, the ultrasonic waves can be detected at different positions of the sample for evaluating the defects. The C-scan images were obtained to analyze the blowholes' position and size. Furthermore, a numerical simulation is also used to research the propagation properties of ultrasound in the specimen with internal holes. Results from the experiment and numerical simulation are discussed and compared to demonstrate the reliability and accuracy of the method.

  3. Nondestructive, in-process inspection of inertia friction welding : an investigation into a new sensing technique.

    SciTech Connect

    Hartman, D. A.; Cola, M. J.; Dave, V. R.; Dozhier, N. G.; Carpenter, R. W.

    2002-01-01

    This paper investigates the capabilities of a new sensor for in-process monitoring of quality during friction welding. The non-contact sensor is composed of microphones that are mounted in an aluminum ring which surrounds the weld joint. The sensor collects the acoustical energy (in the form of sound pressure) that is emitted during the plastic deformation and phase transformations (if applicable) in friction welding processes. The focus in this preliminary investigation is to search for and identify features within the acoustical emission that are indicative of bond quality. Bar-to-bar inertia friction welding (one form of friction welding) of copper to 304L stainless steel is used in this proof-of-concept study. This material combination exhibits only marginal weldability and is ideally suited for validating the capabilities of this new sensing technique. A probabilistic neural network is employed in this work to analyze the acoustical emission's frequency spectrum in an attempt to classify acceptable, conditional, and unacceptable welds. Our preliminary findings indicate that quality-based process features do exist within the frequency spectrum of the acoustical signature. The results from this analysis are presented. Future work in improving the sensing and interpretation of the data is discussed in an effort to develop a robust method of quality-based, in-process monitoring of friction welds.

  4. Nondestructive atomic compositional analysis of BeMgZnO quaternary alloys using ion beam analytical techniques

    NASA Astrophysics Data System (ADS)

    Zolnai, Z.; Toporkov, M.; Volk, J.; Demchenko, D. O.; Okur, S.; Szabó, Z.; Özgür, Ü.; Morkoç, H.; Avrutin, V.; Kótai, E.

    2015-02-01

    The atomic composition with less than 1-2 atom% uncertainty was measured in ternary BeZnO and quaternary BeMgZnO alloys using a combination of nondestructive Rutherford backscattering spectrometry with 1 MeV He+ analyzing ion beam and non-Rutherford elastic backscattering experiments with 2.53 MeV energy protons. An enhancement factor of 60 in the cross-section of Be for protons has been achieved to monitor Be atomic concentrations. Usually the quantitative analysis of BeZnO and BeMgZnO systems is challenging due to difficulties with appropriate experimental tools for the detection of the light Be element with satisfactory accuracy. As it is shown, our applied ion beam technique, supported with the detailed simulation of ion stopping, backscattering, and detection processes allows of quantitative depth profiling and compositional analysis of wurtzite BeZnO/ZnO/sapphire and BeMgZnO/ZnO/sapphire layer structures with low uncertainty for both Be and Mg. In addition, the excitonic bandgaps of the layers were deduced from optical transmittance measurements. To augment the measured compositions and bandgaps of BeO and MgO co-alloyed ZnO layers, hybrid density functional bandgap calculations were performed with varying the Be and Mg contents. The theoretical vs. experimental bandgaps show linear correlation in the entire bandgap range studied from 3.26 eV to 4.62 eV. The analytical method employed should help facilitate bandgap engineering for potential applications, such as solar blind UV photodetectors and heterostructures for UV emitters and intersubband devices.

  5. Non-destructive elemental quantification of polymer-embedded thin films using laboratory based X-ray techniques

    NASA Astrophysics Data System (ADS)

    Cordes, Nikolaus L.; Havrilla, George J.; Usov, Igor O.; Obrey, Kimberly A.; Patterson, Brian M.

    2014-11-01

    Thin coatings are important for a variety of industries including energy (e.g., solar cells, batteries), consumer electronics (e.g., LCD displays, computer chips), and medical devices (e.g., implants). These coatings are typically highly uniform layers with thicknesses ranging from a monolayer up to several micrometers. Characterizing these highly uniform coatings for their thickness, elemental composition, and uniformity are all paramount, but obtaining these measurements can be more difficult when the layers are subsurface and must be interrogated non-destructively. The coupling of confocal micro-X-ray fluorescence (confocal MXRF) and nano-scale X-ray computed tomography (nano-CT) together can make these measurements while meeting these sensitivity and resolution specifications necessary for characterizing thin films. Elemental composition, atomic percent, placement, and uniformity can be measured in three dimensions with this integrated approach. Confocal MXRF uses a pair of polycapillary optics to focus and collect X-rays from a material from a 3D spatially restricted confocal volume. Because of the spatial definition, individual layers (of differing composition) can be characterized based upon the elementally characteristic X-ray fluorescence collected for each element. Nano-scale X-ray computed tomography, in comparison, can image the layers at very high resolution (down to 50 nm) to precisely measure the embedded layer thickness. These two techniques must be used together if both the thickness and atomic density of a layer are unknown. This manuscript will demonstrate that it is possible to measure both the atomic percent of an embedded thin film layer and confirm its manufacturing quality. As a proof of principle, a 1.5 atomic percent, 2 μm-thick Ge layer embedded within polymer capsules, used for laser plasma experiments at the Omega Laser Facility and National Ignition Facility, are measured.

  6. EVITA Project: Comparison Between Traditional Non-Destructive Techniques and Phase Contrast X-Ray Imaging Applied to Aerospace Carbon Fibre Reinforced Polymer

    NASA Astrophysics Data System (ADS)

    Gresil, Matthieu; Revol, Vincent; Kitsianos, Konstantinos; Kanderakis, Georges; Koulalis, Ilias; Sauer, Marc-Olivier; Trétout, Hervé; Madrigal, Ana-Maria

    2016-10-01

    The EU-project EVITA (Non-Destructive EValuation, Inspection and Testing of Primary Aeronautical Composite Structures Using Phase Contrast X-Ray Imaging) aims at bringing Grating-based Phase Contrast X-ray imaging technology to Non-Destructive Evaluation and Inspection of advanced primary and/or complex aerospace composite structures. Grating-based Phase Contrast X-Ray Imaging is based on the so-called Talbot-Lau interferometer, which is made of the combination of a standard X-ray apparatus with three transmission gratings as documented in the literature. This paper presents a comparison of two traditional non-destructive techniques (NDT): ultrasonic through transmission (immersed and water jet) and ultrasonic phased-array pulse echo, with the developed phase contrast X-Ray Imaging applied to advanced aerospace carbon fibre reinforced polymer. Typical defects produced during manufacture is examined as part of the testing and validation procedure. The following defects have been identified as being those most likely to be detected more effectively by the Grating-based Phase Contrast X-Ray Imaging process than other state of the art industrial NDT techniques: porosity, foreign objects, cracks, resin rich, cut fibres, and wavy fibres. The introduction of this innovative methodology is expected to provide the aeronautical industry with a reliable and detailed insight of the integrity of thin and thick composite structures as well as of complex geometry ones, such as integrated closed boxes and sandwiches.

  7. EVITA Project: Comparison Between Traditional Non-Destructive Techniques and Phase Contrast X-Ray Imaging Applied to Aerospace Carbon Fibre Reinforced Polymer

    NASA Astrophysics Data System (ADS)

    Gresil, Matthieu; Revol, Vincent; Kitsianos, Konstantinos; Kanderakis, Georges; Koulalis, Ilias; Sauer, Marc-Olivier; Trétout, Hervé; Madrigal, Ana-Maria

    2017-04-01

    The EU-project EVITA (Non-Destructive EValuation, Inspection and Testing of Primary Aeronautical Composite Structures Using Phase Contrast X-Ray Imaging) aims at bringing Grating-based Phase Contrast X-ray imaging technology to Non-Destructive Evaluation and Inspection of advanced primary and/or complex aerospace composite structures. Grating-based Phase Contrast X-Ray Imaging is based on the so-called Talbot-Lau interferometer, which is made of the combination of a standard X-ray apparatus with three transmission gratings as documented in the literature. This paper presents a comparison of two traditional non-destructive techniques (NDT): ultrasonic through transmission (immersed and water jet) and ultrasonic phased-array pulse echo, with the developed phase contrast X-Ray Imaging applied to advanced aerospace carbon fibre reinforced polymer. Typical defects produced during manufacture is examined as part of the testing and validation procedure. The following defects have been identified as being those most likely to be detected more effectively by the Grating-based Phase Contrast X-Ray Imaging process than other state of the art industrial NDT techniques: porosity, foreign objects, cracks, resin rich, cut fibres, and wavy fibres. The introduction of this innovative methodology is expected to provide the aeronautical industry with a reliable and detailed insight of the integrity of thin and thick composite structures as well as of complex geometry ones, such as integrated closed boxes and sandwiches.

  8. Utilization of nondestructive electrochemical techniques in characterizing microbiologically influenced corrosion (MIC) of API-5L X65 carbon linepipe steel: Laboratory study

    NASA Astrophysics Data System (ADS)

    Al-Abbas, F.; Kakpovbia, A.; Mishra, B.; Olson, D.; Spear, J.

    2012-05-01

    Nondestructive electrochemical techniques were used to investigate the microbiologically influenced corrosion (MIC) by Sulfate Reducing Bacteria (SRB) corrosion of API 5L X65 linepipe steel. These techniques included Electrochemical Impedance Spectroscopy (EIS), open circuit potential (OCP) and linear polarization resistance (Rp). OCP trend showed anodic polarization of 67 mV between the biotic media with reference to abiotic media. These shifts were attributed to the cathodic side reactions produced by the metabolic activity of SRB. Through circuit modeling, EIS results were used to interpret the real time interactions between the electrode, biofilm and solution interfaces.

  9. Overview of the program to assess the reliability of emerging nondestructive techniques open testing and study of flaw type effect on NDE response

    NASA Astrophysics Data System (ADS)

    Meyer, Ryan M.; Komura, Ichiro; Kim, Kyung-cho; Zetterwall, Tommy; Cumblidge, Stephen E.; Prokofiev, Iouri

    2016-02-01

    In February 2012, the U.S. Nuclear Regulatory Commission (NRC) executed agreements with VTT Technical Research Centre of Finland, Nuclear Regulatory Authority of Japan (NRA, former JNES), Korea Institute of Nuclear Safety (KINS), Swedish Radiation Safety Authority (SSM), and Swiss Federal Nuclear Safety Inspectorate (ENSI) to establish the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT). The goal of PARENT is to investigate the effectiveness of current emerging and perspective novel nondestructive examination procedures and techniques to find flaws in nickel-alloy welds and base materials. This is done by conducting a series of open and blind international round-robin tests on a set of large-bore dissimilar metal welds (LBDMW), small-bore dissimilar metal welds (SBDMW), and bottom-mounted instrumentation (BMI) penetration weld test blocks. The purpose of blind testing is to study the reliability of more established techniques and included only qualified teams and procedures. The purpose of open testing is aimed at a more basic capability assessment of emerging and novel technologies. The range of techniques applied in open testing varied with respect to maturity and performance uncertainty and were applied to a variety of simulated flaws. This paper will include a brief overview of the PARENT blind and open testing techniques and test blocks and present some of the blind testing results.

  10. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1993-01-01

    In this Progress Report, we describe our current research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of stitched composite materials and bonded aluminum plate specimens. One purpose of this investigation is to identify and characterize specific features of polar backscatter interrogation which enhance the ability of ultrasound to detect flaws in a stitched composite laminate. Another focus is to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize bonded aluminum lap joints. As an approach to implementing quantitative ultrasonic inspection methods to both of these materials, we focus on the physics that underlies the detection of flaws in such materials.

  11. Evaluation of the quality of commercial silicon carbide wafers by an optical non-destructive inspection technique

    NASA Astrophysics Data System (ADS)

    Hatakeyama, T.; Ichinoseki, K.; Fukuda, K.; Higuchi, N.; Arai, K.

    2008-03-01

    There is a great need for an in-line, high-speed and non-destructive inspection system capable of evaluating and analyzing the quality SiC wafers for SiC power devices. We have examined whether the laser-based optical non-destructive inspection system by KLA-Tencor meets these requirements. By optimizing the optical setup and improving the defect recognition and classification recipe, we have successfully mapped classified defects on a SiC wafer. Using this system, incoming inspection of purchased SiC wafers has been performed. The obtained inspection data show that micropipe density is sufficiently low in a device-grade wafer and, therefore, micropipes are not the main cause of device failure. The next challenges for a device-grade SiC wafer are reduction of epitaxial defects and relatively small defects classified as "particles".

  12. A color video display technique for flow field surveys

    NASA Technical Reports Server (NTRS)

    Winkelmann, A. E.; Tsao, C. P.

    1982-01-01

    Color video display techniques for flow field surveys are presented. The following techniques were examined: traverse device, used for flow field surveys above and behind finite wing models; flow chart of data reduction for color video display technique; location of spanwise survey stations above and behind wing; hot wire data at first three survey stations on fully stalled wing; hot wire data at last three stations behind fully stalled wing; hot wire and pitch probe data; magnitude of velocity, yaw angle, pitch angle, and cross flow direction from 5 tube survey at X/C = 2.70 behind fully stalled wing.

  13. Survey of Radiographic Requirements and Techniques.

    ERIC Educational Resources Information Center

    Farman, Allan G.; Shawkat, Abdul H.

    1981-01-01

    A survey of dental schools revealed little standardization of student requirements for dental radiography in the United States. There was a high degree of variability as to what constituted a full radiographic survey, which has implications concerning the maximum limits to patient exposure to radiation. (Author/MLW)

  14. Survey of Radiographic Requirements and Techniques.

    ERIC Educational Resources Information Center

    Farman, Allan G.; Shawkat, Abdul H.

    1981-01-01

    A survey of dental schools revealed little standardization of student requirements for dental radiography in the United States. There was a high degree of variability as to what constituted a full radiographic survey, which has implications concerning the maximum limits to patient exposure to radiation. (Author/MLW)

  15. NDE: An effective approach to improved reliability and safety. A technology survey. [nondestructive testing of aircraft structures

    NASA Technical Reports Server (NTRS)

    Carpenter, J. L., Jr.; Stuhrke, W. F.

    1976-01-01

    Technical abstracts are presented for about 100 significant documents relating to nondestructive testing of aircraft structures or related structural testing and the reliability of the more commonly used evaluation methods. Particular attention is directed toward acoustic emission; liquid penetrant; magnetic particle; ultrasonics; eddy current; and radiography. The introduction of the report includes an overview of the state-of-the-art represented in the documents that have been abstracted.

  16. Survey Of Present Lens Molding Techniques

    NASA Astrophysics Data System (ADS)

    Pollicove, Harvey M.

    1988-07-01

    This survey will provide an overview of glass molding technologies, with a concentration in the newest of the technologies - Precision Glass Molding (PGM). A brief description of various forms of glass molding, including an historical review of patents associated with precision molding, is given. A worldwide survey of known commercial availability and recent innovations in PGM at Kodak are presented as examples of the potential of the precision molding technology.

  17. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1992-01-01

    The development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of composite materials requires a better understanding of the physics underlying the interaction of ultrasound with the material. The purpose of this investigation is to identify and characterize the features of complex, three dimensional materials that limit the ability of ultrasound to detect flaws in this broad class of emerging materials. In order to explore the interaction of ultrasound with such complex media, we investigate the characteristics of ultrasonic fields which have propagated through samples with complex geometries and/or internal architecture. We focus on the physics that underlies the detection of flaws in such materials.

  18. Nondestructive and rapid concurrent estimation of paracetamol and nimesulide in their combined dosage form using Raman spectroscopic technique.

    PubMed

    Lakhwani, Gargi R; Sherikar, O D; Mehta, Priti J

    2013-03-01

    A rapid, nondestructive Raman spectroscopic method was developed for quantitative estimation of paracetamol and nimesulide in their combined dosage form. A Raman univariate calibration model was developed by measuring the peak intensities of paracetamol and nimesulide at 853 cm(-1) and 1336 cm(-1), respectively. The developed method was successfully applied for in situ, concurrent estimation of paracetamol and nimesulide in their combined dosage and method was also validated according to International Conference on Harmonisation guidelines. Thus, the developed Raman spectroscopic method can be applied for simultaneous estimation of paracetamol and nimesulide in their combined dosage form as a process analytical technology tool by pharmaceutical industries for routine quality control.

  19. Preliminary technique assessment for nondestructive evaluation certification of the NNWSI [Nevada Nuclear Waste Storage Investigations] disposal container closure

    SciTech Connect

    Day, R.A.

    1988-12-31

    Under the direction of the Department of Energy`s (DOE) Office of Civilian Radioactive Waste Management (OCRWM) program, the Nevada Nuclear Waste Storage Investigations (NNWSI) project is evaluating a candidate repository site at Yucca Mountain, Nevada, for permanent disposal of high-level nuclear waste. The Lawrence Livermore National Laboratory (LLNL), a participant in the NNWSI project, is developing waste package designs to meet the NRC requirements. One aspect of this waste package is the nondestructive testing of the final closure of the waste container. The container closure weld can best be nondestructively examined (NDE) by a combination of ultrasonics and liquid penetrants. This combination can be applied remotely and can meet stringent quality control requirements common to nuclear applications. Further development in remote systems and inspection will be required to meet anticipated requirements for flaw detection reliability and sensitivity. New research is not required but might reduce cost or inspection time. Ultrasonic and liquid penetrant methods can examine all closure methods currently being considered, which include fusion welding and inertial welding, among others. These NDE methods also have a history of application in high radiation environments and a well developed technology base for remote operation that can be used to reduce development and design costs. 43 refs., 23 figs., 3 tabs.

  20. A survey of underwater-acoustic ray tracing techniques

    NASA Astrophysics Data System (ADS)

    Jones, R. M.

    1983-06-01

    A survey of techniques and features available in underwater acoustic ray tracing computer programs is presented. The survey includes methods for constructing raypath trajectories, construction eigenrays, ray-intensity calculations, and ray theory corrections. The survey also includes models for sound speed (including interpolation methods), ocean bottom (including both bathymetry and reflection coefficient), ocean surface reflection coefficient, dissipation, temperature, salinity, and ocean current. In addition, methods for displaying models and methods for presenting ray tracing results are surveyed.

  1. Primary Water Stress Corrosion Cracks in Nickel Alloy Dissimilar Metal Welds: Detection and Sizing Using Established and Emerging Nondestructive Examination Techniques

    SciTech Connect

    Braatz, Brett G.; Cumblidge, Stephen E.; Doctor, Steven R.; Prokofiev, Iouri

    2012-12-31

    The U.S. Nuclear Regulatory Commission has established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) as a follow-on to the international cooperative Program for the Inspection of Nickel Alloy Components (PINC). The goal of PINC was to evaluate the capabilities of various nondestructive evaluation (NDE) techniques to detect and characterize surface-breaking primary water stress corrosion cracks in dissimilar-metal welds (DMW) in bottom-mounted instrumentation (BMI) penetrations and small-bore (≈400-mm diameter) piping components. A series of international blind round-robin tests were conducted by commercial and university inspection teams. Results from these tests showed that a combination of conventional and phased-array ultrasound techniques provided the highest performance for flaw detection and depth sizing in dissimilar metal piping welds. The effective detection of flaws in BMIs by eddy current and ultrasound shows that it may be possible to reliably inspect these components in the field. The goal of PARENT is to continue the work begun in PINC and apply the lessons learned to a series of open and blind international round-robin tests that will be conducted on a new set of piping components including large-bore (≈900-mm diameter) DMWs, small-bore DMWs, and BMIs. Open round-robin testing will engage universities and industry worldwide to investigate the reliability of emerging NDE techniques to detect and accurately size flaws having a wide range of lengths, depths, orientations, and locations. Blind round-robin testing will invite testing organizations worldwide, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from easy to very difficult to detect and size. This paper presents highlights of PINC and reports on the plans and progress for

  2. Nondestructive analysis and development

    NASA Technical Reports Server (NTRS)

    Moslehy, Faissal A.

    1993-01-01

    This final report summarizes the achievements of project #4 of the NASA/UCF Cooperative Agreement from January 1990 to December 1992. The objectives of this project are to review NASA's NDE program at Kennedy Space Center (KSC) and recommend means for enhancing the present testing capabilities through the use of improved or new technologies. During the period of the project, extensive development of a reliable nondestructive, non-contact vibration technique to determine and quantify the bond condition of the thermal protection system (TPS) tiles of the Space Shuttle Orbiter was undertaken. Experimental modal analysis (EMA) is used as a non-destructive technique for the evaluation of Space Shuttle thermal protection system (TPS) tile bond integrity. Finite element (FE) models for tile systems were developed and were used to generate their vibration characteristics (i.e. natural frequencies and mode shapes). Various TPS tile assembly configurations as well as different bond conditions were analyzed. Results of finite element analyses demonstrated a drop in natural frequencies and a change in mode shapes which correlate with both size and location of disbond. Results of experimental testing of tile panels correlated with FE results and demonstrated the feasibility of EMA as a viable technique for tile bond verification. Finally, testing performed on the Space Shuttle Columbia using a laser doppler velocimeter demonstrated the application of EMA, when combined with FE modeling, as a non-contact, non-destructive bond evaluation technique.

  3. Evaluation of the veracity of one work by the artist Di Cavalcanti through non-destructive techniques: XRF, imaging and brush stroke analysis

    NASA Astrophysics Data System (ADS)

    Kajiya, E. A. M.; Campos, P. H. O. V.; Rizzutto, M. A.; Appoloni, C. R.; Lopes, F.

    2014-02-01

    This paper presents systematic studies and analysis that contributed to the identification of the forgery of a work by the artist Emiliano Augusto Cavalcanti de Albuquerque e Melo, known as Di Cavalcanti. The use of several areas of expertise such as brush stroke analysis ("pinacologia"), applied physics, and art history resulted in an accurate diagnosis for ascertaining the authenticity of the work entitled "Violeiro" (1950). For this work we used non-destructive methods such as techniques of infrared, ultraviolet, visible and tangential light imaging combined with chemical analysis of the pigments by portable X-Ray Fluorescence (XRF) and graphic gesture analysis. Each applied method of analysis produced specific information that made possible the identification of materials and techniques employed and we concluded that this work is not consistent with patterns characteristic of the artist Di Cavalcanti.

  4. Diurnal activity of four species of thrips (Thysanoptera: Thripidae) and efficiencies of three nondestructive sampling techniques for thrips in mango inflorescences.

    PubMed

    Aliakbarpour, H; Rawi, Che Salmah Md

    2010-06-01

    Thrips cause considerable economic loss to mango, Mangifera indica L., in Penang, Malaysia. Three nondestructive sampling techniques--shaking mango panicles over a moist plastic tray, washing the panicles with ethanol, and immobilization of thrips by using CO2--were evaluated for their precision to determine the most effective technique to capture mango flower thrips (Thysanoptera: Thripidae) in an orchard located at Balik Pulau, Penang, Malaysia, during two flowering seasons from December 2008 to February 2009 and from August to September 2009. The efficiency of each of the three sampling techniques was compared with absolute population counts on whole panicles as a reference. Diurnal flight activity of thrips species was assessed using yellow sticky traps. All three sampling methods and sticky traps were used at two hourly intervals from 0800 to 1800 hours to get insight into diurnal periodicity of thrips abundance in the orchard. Based on pooled data for the two seasons, the CO2 method was the most efficient procedure extracting 80.7% adults and 74.5% larvae. The CO2 method had the lowest relative variation and was the most accurate procedure compared with the absolute method as shown by regression analysis. All collection techniques showed that the numbers of all thrips species in mango panicles increased after 0800 hours, reaching a peak between 1200 and 1400 hours. Adults thrips captured on the sticky traps were the most abundant between 0800-1000 and 1400-1600 hours. According to results of this study, the CO2 method is recommended for sampling of thrips in the field. It is a nondestructive sampling procedure that neither damages flowers nor diminishes fruit production. Management of thrips populations in mango orchards with insecticides would be more effectively carried out during their peak population abundance on the flower panicles at midday to 1400 hours.

  5. Non-destructive and non-invasive analyses shed light on the realization technique of ancient polychrome prints

    NASA Astrophysics Data System (ADS)

    Striová, Jana; Coccolini, Gabriele; Micheli, Sara; Lofrumento, Cristiana; Galeotti, Monica; Cagnini, Andrea; Castellucci, Emilio Mario

    2009-08-01

    Five polychrome prints representing famous painters, such as Albrecht Dürer, were analyzed using a non-destructive and non-invasive methodology as required by the artwork typology. The diagnostic strategy includes X-ray fluorescence (XRF), reflectance micro-infrared (μFTIR) and micro-Raman (μRaman) spectroscopy. These prints were realized with a la poupée method that involves application of the polychrome inks on a single copper plate, before the printing process. A broad range of compounds (i.e., cinnabar, red lead, white lead, umber earth, hydrated calcium sulfate, calcium carbonate, amorphous carbon, and Prussian blue) was employed as chalcographic inks, using linseed oil as a binding medium. Gamboge was identified in the delicate finishing brush touches realized in watercolor.

  6. Non-destructive and non-invasive analyses shed light on the realization technique of ancient polychrome prints.

    PubMed

    Striová, Jana; Coccolini, Gabriele; Micheli, Sara; Lofrumento, Cristiana; Galeotti, Monica; Cagnini, Andrea; Castellucci, Emilio Mario

    2009-08-01

    Five polychrome prints representing famous painters, such as Albrecht Dürer, were analyzed using a non-destructive and non-invasive methodology as required by the artwork typology. The diagnostic strategy includes X-ray fluorescence (XRF), reflectance micro-infrared (microFTIR) and micro-Raman (microRaman) spectroscopy. These prints were realized with a la poupée method that involves application of the polychrome inks on a single copper plate, before the printing process. A broad range of compounds (i.e., cinnabar, red lead, white lead, umber earth, hydrated calcium sulfate, calcium carbonate, amorphous carbon, and Prussian blue) was employed as chalcographic inks, using linseed oil as a binding medium. Gamboge was identified in the delicate finishing brush touches realized in watercolor.

  7. Improvement of interfacial adhesion and nondestructive damage evaluation for plasma-treated PBO and Kevlar fibers/epoxy composites using micromechanical techniques and surface wettability.

    PubMed

    Park, Joung-Man; Kim, Dae-Sik; Kim, Sung-Ryong

    2003-08-15

    Comparison of interfacial properties and microfailure mechanisms of oxygen-plasma treated poly(p-phenylene-2,6-benzobisoxazole (PBO, Zylon) and poly(p-phenylene terephthalamide) (PPTA, Kevlar) fibers/epoxy composites were investigated using a micromechanical technique and nondestructive acoustic emission (AE). The interfacial shear strength (IFSS) and work of adhesion, Wa, of PBO or Kevlar fiber/epoxy composites increased with oxygen-plasma treatment, due to induced hydrogen and covalent bondings at their interface. Plasma-treated Kevlar fiber showed the maximum critical surface tension and polar term, whereas the untreated PBO fiber showed the minimum values. The work of adhesion and the polar term were proportional to the IFSS directly for both PBO and Kevlar fibers. The microfibril fracture pattern of two plasma-treated fibers appeared obviously. Unlike in slow cooling, in rapid cooling, case kink band and kicking in PBO fiber appeared, whereas buckling in the Kevlar fiber was observed mainly due to compressive and residual stresses. Based on the propagation of microfibril failure toward the core region, the number of AE events for plasma-treated PBO and Kevlar fibers increased significantly compared to the untreated case. The results of nondestructive AE were consistent with microfailure modes.

  8. Complementary use of the Raman and XRF techniques for non-destructive analysis of historical paint layers

    NASA Astrophysics Data System (ADS)

    Sawczak, M.; Kamińska, A.; Rabczuk, G.; Ferretti, M.; Jendrzejewski, R.; Śliwiński, G.

    2009-03-01

    The portable XRF spectrometer has been applied in situ for the non-destructive elemental mapping of the pigment components of the XV c. mural painting and frescos of the Little Christopher chamber in the Main Town Hall of Gdańsk, Poland. For a sufficiently large data collection the principal component analysis (PCA) was applied in order to associate the most intense lines of the elements Ca, Cu, Fe, Pb, and Hg in the XRF spectra with the palette of colors: white, brown, green, blue, red, yellow, and black observed in the painting. This allowed to limit the number of extractions of the micro-samples for the complementary Raman measurements thus assuring the practically non-destructive character of the entire analysis. The reliable identification of the pigment compositions was based on coincidence of the XRF, PCA and the Raman results which confirmed the presence of the chalk, malachite, azurite, red lead, mars red, mars yellow and candle black in the historical paints, except of the carbon-based black pigment being out of the XRF detection range. Different hues of the green paint were specified and the variety of the red and brown ones was ascribed to compositions of the Pb- and Fe-based red pigments (Fe 2O 3 and Pb 3O 4) with addition of the vermilion (HgS) and carbon black, in agreement with literature. The traces of elements: Ba and Sr, Sb and Mo, and also Cd, were ascribed to the impurities of Ca, those of some ochre pigments, and to the soluble Cd salts, respectively.

  9. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1994-01-01

    In this Progress Report, we describe our continuing research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the inspection and characterization of complex composite structures. We explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. As an initial step toward the application of linear array imaging technology to the interrogation of a wide range of complex composite structures, we present images obtained using an unmodified medical ultrasonic imaging system of two epoxy-bonded aluminum plate specimens, each with intentionally disbonded regions. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to assess whether these images can detect disbonded regions and provide information regarding the nature of the disbonded region. We present a description of a standoff/delay fixture which has been designed, constructed, and implemented on a Hewlett-Packard SONOS 1500 medical imaging system. This standoff/delay fixture, when attached to a 7.5 MHz linear array probe, greatly enhances our ability to interrogate flat plate specimens. The final section of this Progress Report describes a woven composite plate specimen that has been specially machined to include intentional flaws. This woven composite specimen will allow us to assess the feasibility of applying linear array imaging technology to the inspection and characterization of complex textile composite materials. We anticipate the results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology.

  10. High-resolution X-ray imaging—a powerful nondestructive technique for applications in semiconductor industry

    NASA Astrophysics Data System (ADS)

    Zschech, Ehrenfried; Yun, Wenbing; Schneider, Gerd

    2008-08-01

    The availability of high-brilliance X-ray sources, high-precision X-ray focusing optics and very efficient CCD area detectors has contributed essentially to the development of transmission X-ray microscopy (TXM) and X-ray computed tomography (XCT) with sub-50 nm resolution. Particularly, the fabrication of high aspect ratio Fresnel zone plates with zone widths approaching 15 nm has contributed to the enormous improvement in spatial resolution during the previous years. Currently, Fresnel zone plates give the ability to reach spatial resolutions of 15 to 20 nm in the soft and of about 30 to 50 nm in the hard X-ray energy range. X-ray microscopes with rotating anode X-ray sources that can be installed in an analytical lab next to a semiconductor fab have been developed recently. These unique TXM/XCT systems provide an important new capability of nondestructive 3D imaging of internal circuit structures without destructive sample preparation such as cross sectioning. These lab systems can be used for failure localization in micro- and nanoelectronic structures and devices, e.g., to visualize voids and residuals in on-chip metal interconnects without physical modification of the chip. Synchrotron radiation experiments have been used to study new processes and materials that have to be introduced into the semiconductor industry. The potential of TXM using synchrotron radiation in the soft X-ray energy range is shown for the nondestructive in situ imaging of void evolution in embedded on-chip copper interconnect structures during electromigration and for the imaging of different types of insulating thin films between the on-chip interconnects (spectromicroscopy).

  11. Survey of air cargo forecasting techniques

    NASA Technical Reports Server (NTRS)

    Kuhlthan, A. R.; Vermuri, R. S.

    1978-01-01

    Forecasting techniques currently in use in estimating or predicting the demand for air cargo in various markets are discussed with emphasis on the fundamentals of the different forecasting approaches. References to specific studies are cited when appropriate. The effectiveness of current methods is evaluated and several prospects for future activities or approaches are suggested. Appendices contain summary type analyses of about 50 specific publications on forecasting, and selected bibliographies on air cargo forecasting, air passenger demand forecasting, and general demand and modalsplit modeling.

  12. Superresolution imaging: a survey of current techniques

    NASA Astrophysics Data System (ADS)

    Cristóbal, G.; Gil, E.; Šroubek, F.; Flusser, J.; Miravet, C.; Rodríguez, F. B.

    2008-08-01

    Imaging plays a key role in many diverse areas of application, such as astronomy, remote sensing, microscopy, and tomography. Owing to imperfections of measuring devices (e.g., optical degradations, limited size of sensors) and instability of the observed scene (e.g., object motion, media turbulence), acquired images can be indistinct, noisy, and may exhibit insuffcient spatial and temporal resolution. In particular, several external effects blur images. Techniques for recovering the original image include blind deconvolution (to remove blur) and superresolution (SR). The stability of these methods depends on having more than one image of the same frame. Differences between images are necessary to provide new information, but they can be almost unperceivable. State-of-the-art SR techniques achieve remarkable results in resolution enhancement by estimating the subpixel shifts between images, but they lack any apparatus for calculating the blurs. In this paper, after introducing a review of current SR techniques we describe two recently developed SR methods by the authors. First, we introduce a variational method that minimizes a regularized energy function with respect to the high resolution image and blurs. In this way we establish a unifying way to simultaneously estimate the blurs and the high resolution image. By estimating blurs we automatically estimate shifts with subpixel accuracy, which is inherent for good SR performance. Second, an innovative learning-based algorithm using a neural architecture for SR is described. Comparative experiments on real data illustrate the robustness and utilization of both methods.

  13. A comparison of two waterfowl brood survey techniques

    Treesearch

    Mark A. Rumble; Lester D. Flake

    1982-01-01

    Aerial surveys, brood beat outs, road surveys, and brood observations have been used to estimate numbers of waterfowl broods (M. E. Anderson, unpubl. reps., South Dakota Dep. Game, Fish, and Parks Fed. Aid Proj. W-17-R-7 and 8,1953, 1955; Bennett 1967). M. C. Hammond (unpubl. rep., U.S. Bur. Sport Fish and Wildl., 1970) summarized several brood survey techniques and...

  14. Survey of Software Assurance Techniques for Highly Reliable Systems

    NASA Technical Reports Server (NTRS)

    Nelson, Stacy

    2004-01-01

    This document provides a survey of software assurance techniques for highly reliable systems including a discussion of relevant safety standards for various industries in the United States and Europe, as well as examples of methods used during software development projects. It contains one section for each industry surveyed: Aerospace, Defense, Nuclear Power, Medical Devices and Transportation. Each section provides an overview of applicable standards and examples of a mission or software development project, software assurance techniques used and reliability achieved.

  15. Emerging Technologies and Techniques for Wide Area Radiological Survey and Remediation

    SciTech Connect

    Sutton, M.; Zhao, P.

    2016-03-24

    Technologies to survey and decontaminate wide-area contamination and process the subsequent radioactive waste have been developed and implemented following the Chernobyl nuclear power plant release and the breach of a radiological source resulting in contamination in Goiania, Brazil. These civilian examples of radioactive material releases provided some of the first examples of urban radiological remediation. Many emerging technologies have recently been developed and demonstrated in Japan following the release of radioactive cesium isotopes (Cs-134 and Cs-137) from the Fukushima Dai-ichi nuclear power plant in 2011. Information on technologies reported by several Japanese government agencies, such as the Japan Atomic Energy Agency (JAEA), the Ministry of the Environment (MOE) and the National Institute for Environmental Science (NIES), together with academic institutions and industry are summarized and compared to recently developed, deployed and available technologies in the United States. The technologies and techniques presented in this report may be deployed in response to a wide area contamination event in the United States. In some cases, additional research and testing is needed to adequately validate the technology effectiveness over wide areas. Survey techniques can be deployed on the ground or from the air, allowing a range of coverage rates and sensitivities. Survey technologies also include those useful in measuring decontamination progress and mapping contamination. Decontamination technologies and techniques range from non-destructive (e.g., high pressure washing) and minimally destructive (plowing), to fully destructive (surface removal or demolition). Waste minimization techniques can greatly impact the long-term environmental consequences and cost following remediation efforts. Recommendations on technical improvements to address technology gaps are presented together with observations on remediation in Japan.

  16. Potential applicability of stress wave velocity method on pavement base materials as a non-destructive testing technique

    NASA Astrophysics Data System (ADS)

    Mahedi, Masrur

    Aggregates derived from natural sources have been used traditionally as the pavement base materials. But in recent times, the extraction of these natural aggregates has become more labor intensive and costly due to resource depletion and environmental concerns. Thus, the uses of recycled aggregates as the supplementary of natural aggregates are increasing considerably in pavement construction. Use of recycled aggregates such as recycled crushed concrete (RCA) and recycled asphalt pavement (RAP) reduces the rate of natural resource depletion, construction debris and cost. Although recycled aggregates could be used as a viable alternative of conventional base materials, strength characteristics and product variability limit their utility to a great extent. Hence, their applicability is needed to be evaluated extensively based on strength, stiffness and cost factors. But for extensive evaluation, traditionally practiced test methods are proven to be unreasonable in terms of time, cost, reliability and applicability. On the other hand, rapid non-destructive methods have the potential to be less time consuming and inexpensive along with the low variability of test results; therefore improving the reliability of estimated performance of the pavement. In this research work, the experimental program was designed to assess the potential application of stress wave velocity method as a non-destructive test in evaluating recycled base materials. Different combinations of cement treated recycled concrete aggregate (RAP) and recycled crushed concrete (RCA) were used to evaluate the applicability of stress wave velocity method. It was found that, stress wave velocity method is excellent in characterizing the strength and stiffness properties of cement treated base materials. Statistical models, based on P-wave velocity were derived for predicting the modulus of elasticity and compressive strength of different combinations of cement treated RAP, Grade-1 and Grade-2 materials. Two

  17. [The Non-Destructive Analysis of Some Ancient Jade Artifacts Unearthed from Henan Province by a Variety of Optical Techniques].

    PubMed

    Wang, Kai; Dong, Jun-qing; Zhao, Hong-xia; Gan, Fu-xi; Hu, Yong-qing; Pan, Wen-quan

    2015-09-01

    A total of 14 pieces of ancient jade artifact unearthed from Henan Province were non-destructively analyzed by means of a portable X-ray fluorescence spectrometer (pXRF), laser Raman spectroscopy (portable and mobile) and optical coherence tomography (OCT) technology, comprehensively. The raw materials of ancient jade artifacts could be determined accurately through the combination of pXRF and portable Raman spectrometer in a short time. With the advantages of small size and easy-operation, these two instruments are suitable to in situ non-destructive analysis of ancient jade artifacts. The results of the pXRF shows that these ancient jade artifacts can be divided into 6 categories such as rich in Si Al K, rich in Ca, rich in Si Ca, rich in Si Mg, rich in Si, rich in Ca P. Their main phases have been successfully identified by the portable Raman spectrometer. In the lab, the mobile confocal laser Raman spectrometer, which help us find the Raman vibration peak of [OH] in the tremolite jade, is used to make up the disadvantages of the portable Raman spectrometer such as lower spectral resolution, lower accuracy and narrower measuring range. We can use the OCT to analyze the transparency, fiber fineness and inclusion etc. of the jade artifacts. The confocal laser Raman spectroscopy combined with OCT is used to analyze 2 containing inclusion of tremolite jade samples. OCT image can visually display the distribution characteristics of the inclusion in these 2 samples. Confocal laser Raman spectroscopy can accurately locate the sample surface of inclusion, then we can observe the micro morphology and analyze its phase. The results show that the black inclusion is graphite. This work is very significant to study the geographical origin of jade. Through the study we find, the use of pXRF, laser Raman spectroscopy (portable and mobile) and OCT can be achieved on the identification and analysis of cultural relic's phase composition and texture feature and meet the basic

  18. Nondestructive imaging of small size voids at Akrotiri archaeological site, Thera Island, Greece, by seismic inversion techniques

    NASA Astrophysics Data System (ADS)

    Louis, Filippos I.; Clark, Roger A.; Louis, Ioannis F.; Makropoulos, Costas C.

    2005-07-01

    High-resolution travel time tomography was used to explore the volcanic basement rock at the Akrotiri archaeological site, Thera (Santorini) Island. The survey was carried out in the context of a large scale project, in which the protective roof cover of old monuments is being replaced by a new environmentally friendly structure, which will be supported by 95 pillars drilled into the volcanic basement rock. Man-made or natural cavities (empty or half-filled with stones), ceramics, and other materials of archaeological interest were unveiled during the excavation of foundation shafts. The objective of this geophysical investigation was the detection of such voids in the vicinity of the excavated shafts, so that the overhead structure can be better supported and protected in the case of an earthquake event. The cross-hole seismic tomography technique was adopted for this purpose. A number of synthetic examples and a calibration experiment at a shaft with a known natural cavity clearly indicated that the tomographic inversion is capable of providing high-resolution 2-D velocity models. High S/N ratios ensured field seismic records of high quality. A set of stability tests was run to check the consistency of the method. Travel time residuals verified the validity of the final velocity depth sections, while model complexity trends showed a consistency between models after a certain number of iterations. The reconstructed velocity fields were quite consistent with the expected velocity structures based on the geologic descriptions of formations encountered during the drilling of the shafts. Impressive low-velocity structures attributed to natural or man-made cavities were reported to the constructing group of engineers, and a remedial action plan was being undertaken to support and improve the ground behavior.

  19. Nondestructive measurement of total volatile basic nitrogen (TVB-N) in pork meat by integrating near infrared spectroscopy, computer vision and electronic nose techniques.

    PubMed

    Huang, Lin; Zhao, Jiewen; Chen, Quansheng; Zhang, Yanhua

    2014-02-15

    Total volatile basic nitrogen (TVB-N) content is an important reference index for evaluating pork freshness. This paper attempted to measure TVB-N content in pork meat using integrating near infrared spectroscopy (NIRS), computer vision (CV), and electronic nose (E-nose) techniques. In the experiment, 90 pork samples with different freshness were collected for data acquisition by three different techniques, respectively. Then, the individual characteristic variables were extracted from each sensor. Next, principal component analysis (PCA) was used to achieve data fusion based on these characteristic variables from 3 different sensors data. Back-propagation artificial neural network (BP-ANN) was used to construct the model for TVB-N content prediction, and the top principal components (PCs) were extracted as the input of model. The result of the model was achieved as follows: the root mean square error of prediction (RMSEP) = 2.73 mg/100g and the determination coefficient (R(p)(2)) = 0.9527 in the prediction set. Compared with single technique, integrating three techniques, in this paper, has its own superiority. This work demonstrates that it has the potential in nondestructive detection of TVB-N content in pork meat using integrating NIRS, CV and E-nose, and data fusion from multi-technique could significantly improve TVB-N prediction performance. Copyright © 2013. Published by Elsevier Ltd.

  20. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy

    PubMed Central

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-01-01

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion. PMID:27025266

  1. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy.

    PubMed

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-03-30

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion.

  2. Non-destructive method of characterisation of radioactive waste containers using gamma spectroscopy and Monte Carlo techniques.

    PubMed

    Ridikas, D; Feray, S; Cometto, M; Damoy, F

    2005-01-01

    During the decommissioning of the SATURNE accelerator at CEA Saclay (France), a number of concrete containers with radioactive materials of low or very low activity had to be characterised before their final storage. In this paper, a non-destructive approach combining gamma ray spectroscopy and Monte Carlo simulations is used in order to characterise massive concrete blocks containing some radioactive waste. The limits and uncertainties of the proposed method are quantified for the source term activity estimates using 137Cs as a tracer element. A series of activity measurements with a few representative waste containers were performed before and after destruction. It has been found that neither was the distribution of radioactive materials homogeneous nor was its density unique, and this became the major source of systematic errors in this study. Nevertheless, we conclude that by combining gamma ray spectroscopy and full scale Monte Carlo simulations one can estimate the source term activity for some tracer elements such as 134Cs, 137Cs, 60Co, etc. The uncertainty of this estimation should not be bigger than a factor of 2-3.

  3. Non-destructive testing techniques based on nonlinear methods for assessment of debonding in single lap joints

    NASA Astrophysics Data System (ADS)

    Scarselli, G.; Ciampa, F.; Ginzburg, D.; Meo, M.

    2015-04-01

    Nonlinear ultrasonic non-destructive evaluation (NDE) methods can be used for the identification of defects within adhesive bonds as they rely on the detection of nonlinear elastic features for the evaluation of the bond strength. In this paper the nonlinear content of the structural response of a single lap joint subjected to ultrasonic harmonic excitation is both numerically and experimentally evaluated to identify and characterize the defects within the bonded region. Different metallic samples with the same geometry were experimentally tested in order to characterize the debonding between two plates by using two surface bonded piezoelectric transducers in pitch-catch mode. The dynamic response of the damaged samples acquired by the single receiver sensor showed the presence of higher harmonics (2nd and 3rd) and subharmonics of the fundamental frequencies. These nonlinear elastic phenomena are clearly due to nonlinear effects induced by the poor adhesion between the two plates. A new constitutive model aimed at representing the nonlinear material response generated by the interaction of the ultrasonic waves with the adhesive joint is also presented. Such a model is implemented in an explicit FE software and uses a nonlinear user defined traction-displacement relationship implemented by means of a cohesive material user model interface. The developed model is verified for the different geometrical and material configurations. Good agreement between the experimental and numerical nonlinear response showed that this model can be used as a simple and useful tool for understanding the quality of the adhesive joint.

  4. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1995-01-01

    In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

  5. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Astrophysics Data System (ADS)

    Miller, James G.

    1995-03-01

    In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

  6. A survey of compiler optimization techniques

    NASA Technical Reports Server (NTRS)

    Schneck, P. B.

    1972-01-01

    Major optimization techniques of compilers are described and grouped into three categories: machine dependent, architecture dependent, and architecture independent. Machine-dependent optimizations tend to be local and are performed upon short spans of generated code by using particular properties of an instruction set to reduce the time or space required by a program. Architecture-dependent optimizations are global and are performed while generating code. These optimizations consider the structure of a computer, but not its detailed instruction set. Architecture independent optimizations are also global but are based on analysis of the program flow graph and the dependencies among statements of source program. A conceptual review of a universal optimizer that performs architecture-independent optimizations at source-code level is also presented.

  7. A Paradigm for the Nondestructive Assay of Spent Fuel Assemblies and Similar Large Objects, with Emphasis on the Role of Photon-Based Techniques

    NASA Astrophysics Data System (ADS)

    Bolind, Alan Michael

    2015-10-01

    The practice of nondestructive assay (NDA) of nuclear materials has, until now, been focused primarily (1) on smaller objects (2) with less fissile material and (3) with less self-generated radiation. The transition to the application of NDA to spent fuel assemblies and similar large objects violates these three conditions, thereby bringing the assumptions and paradigm of traditional NDA practice into question for the new applications. In this paper, a new paradigm for these new applications is presented which is based on the fundamental principles of nuclear engineering. It is shown that the NDA of spent fuel assemblies is mostly a three-dimensional problem that requires the integration of three independent NDA measurements in order to achieve a unique and accurate assay. The only NDA techniques that can avoid this requirement are those that analyze signals that are characteristic to specific isotopes (such as those caused by characteristic resonance interactions), and that are neither distorted nor overly attenuated by the other surrounding material. Some photon-based NDA techniques fall into this exceptional category. Such exceptional NDA techniques become essential to employ when assaying large objects that, unlike spent fuel assemblies, do not have a consistent geometry. With this new NDA paradigm, the advanced photon-based NDA techniques can be put into their proper context, and their development can thereby be properly motivated.

  8. Machine-assisted verification of latent fingerprints: first results for nondestructive contact-less optical acquisition techniques with a CWL sensor

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Mario; Kiltz, Stefan; Krapyvskyy, Dmytro; Dittmann, Jana; Vielhauer, Claus; Leich, Marcus

    2011-11-01

    A machine-assisted analysis of traces from crime scenes might be possible with the advent of new high-resolution non-destructive contact-less acquisition techniques for latent fingerprints. This requires reliable techniques for the automatic extraction of fingerprint features from latent and exemplar fingerprints for matching purposes using pattern recognition approaches. Therefore, we evaluate the NIST Biometric Image Software for the feature extraction and verification of contact-lessly acquired latent fingerprints to determine potential error rates. Our exemplary test setup includes 30 latent fingerprints from 5 people in two test sets that are acquired from different surfaces using a chromatic white light sensor. The first test set includes 20 fingerprints on two different surfaces. It is used to determine the feature extraction performance. The second test set includes one latent fingerprint on 10 different surfaces and an exemplar fingerprint to determine the verification performance. This utilized sensing technique does not require a physical or chemical visibility enhancement of the fingerprint residue, thus the original trace remains unaltered for further investigations. No particular feature extraction and verification techniques have been applied to such data, yet. Hence, we see the need for appropriate algorithms that are suitable to support forensic investigations.

  9. Proceedings for the nondestructive assay and nondestructive examination waste characterization conference. No. 5

    SciTech Connect

    1997-05-01

    This report contains paper presented at the 5th Nondestructive Assay and nondestructive Examination Waste Characterization conference. Topics included compliance, neutron NDA techniques, gamma NDA techniques, tomographic methods, and NDA modality and information combination techniques. Individual reports have been processed separately for the United States Department of Energy databases.

  10. Laser ultrasound for nondestructive testing

    NASA Astrophysics Data System (ADS)

    Scott, W. R.

    1982-03-01

    Noncontact techniques for generating and detecting high frequency ultrasonic waves ( 1 MHz) are being explored using pulsed laser thermoelastic transduction and heterodyne interferometry respectively. In addition, holographic projection techniques are being investigated for beam shaping and beam steering of the thermoelastic waves. Possible applications of this technology include performance of ultrasonic nondestructive testing in hostile or inaccessible environments.

  11. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    SciTech Connect

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

  12. Feasibility on Ultrasonic Velocity using Contact and Non-Contact Nondestructive Techniques for Carbon/Carbon Composites

    NASA Astrophysics Data System (ADS)

    Im, K. H.; Chang, M.; Hsu, D. K.; Song, S. J.; Cho, H.; Park, J. W.; Kweon, Y. S.; Sim, J. K.; Yang, I. Y.

    2007-03-01

    Advanced materials are to be required to have specific functions associated with extremely environments. One of them is carbon/carbon(C/C) composite material, which has obvious advantages over conventional materials. The C/Cs have become to be utilized as parts of aerospace applications and its low density, high thermal conductivity and excellent mechanical properties at elevated temperatures make it an ideal material for aircraft brake disks. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. In this work, a C/C composite material was characterized with non-contact and contact ultrasonic methods using a scanner with automatic-data acquisition function. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake were compared and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude of the ultrasonic pulse was used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the dry-coupling ultrasonic UT system and through transmission method in immersion. Finally, feasibility has been found to measure and compare ultrasonic velocities of C/C composites with using the contact/noncontact peak-delay measurement method based on the pulse overlap method.

  13. Two-dimensional simulation of the single-sided air-coupled ultrasonic pitch-catch technique for non-destructive testing.

    PubMed

    Delrue, Steven; Van Den Abeele, Koen; Blomme, Erik; Deveugele, Jurgen; Lust, Pieter; Matar, Olivier Bou

    2010-02-01

    Non-contact air-coupled ultrasonic inspection of materials using single-sided access offers interesting possibilities for the development of in-line non-destructive testing (NDT) systems. This contribution reports observations and simulations obtained from a single-sided air-coupled pitch-catch configuration. The pitch-catch technique involves a set-up in which transmitter and receiver are located at the same side of the test object. Sound waves, reflected once or multiple times from the back-wall of the object or refracted by a discontinuity, are recorded and analyzed for visualization. The feasibility of the technique is demonstrated, experimentally, in the case of artificial defects in aluminium samples. Depending on the configuration one or more ultrasonic images of the defect can be observed, their number and relative position containing information about the location of the defect. The experiments are simulated using two distinctive methods. The first simulation is based on a ray tracing (shadow) approach, the second method uses a spectral solution implemented within COMSOL. Both simulation methods allow simple prediction of the response images in experimental conditions with supplementary levels of complexity, which will assist the development and optimization of online inspection techniques.

  14. Nondestructive evaluations

    SciTech Connect

    Kulkarni, S.

    1993-03-01

    This report discusses Nondestructive Evaluation (NDE) thrust area which supports initiatives that advance inspection science and technology. The goal of the NDE thrust area is to provide cutting-edge technologies that have promise of inspection tools three to five years in the future. In selecting projects, the thrust area anticipates the needs of existing and future Lawrence Livermore National Laboratory (LLNL) programs. NDE provides materials characterization inspections, finished parts, and complex objects to find flaws and fabrication defects and to determine their physical and chemical characteristics. NDE also encompasses process monitoring and control sensors and the monitoring of in-service damage. For concurrent engineering, NDE becomes a frontline technology and strongly impacts issues of certification and of life prediction and extension. In FY-92, in addition to supporting LLNL programs and the activities of nuclear weapons contractors, NDE has initiated several projects with government agencies and private industries to study aging infrastructures and to advance manufacturing processes. Examples of these projects are (1) the Aging Airplanes Inspection Program for the Federal Aviation Administration, (2) Signal Processing of Acoustic Signatures of Heart Valves for Shiley, Inc.; and (3) Turbine Blade Inspection for the Air Force, jointly with Southwest Research Institute and Garrett. In FY-92, the primary contributions of the NDE thrust area, described in this report were in fieldable chemical sensor systems, computed tomography, and laser generation and detection of ultrasonic energy.

  15. The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials.

    PubMed

    Mulware, Stephen Juma

    2015-01-01

    The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented.

  16. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Tenth quarterly report, January-March 1980

    SciTech Connect

    Kupperman, D.S.; Yuhas, D.; Caines, M.J.

    1980-04-01

    The effectiveness of several conventional and unconventional NDE techniques for specific high-temperature ceramic components was determined. Techniques under study at ANL include dye-enhanced radiography, acoustic microscopy, conventional ultrasonic testing, acoustic-emission detection, acoustic impact testing, holography, interferometry, infrared scanning, internal friction measurements, and overload proof testing. The current effort involves SiC heat-exchanger tubes; previous ceramic NDE efforts at ANL have involved silicon-nitride gas-turbine rotors. Recent results on inspection of SiC heat-exchanger tubing by means of ultrasonic acoustic microscopy techniques and efforts initiated and planned for NDE of ceramic joints are discussed.

  17. Nondestructive testing with thermography

    NASA Astrophysics Data System (ADS)

    Ibarra-Castanedo, Clemente; Tarpani, José Ricardo; Maldague, Xavier P. V.

    2013-11-01

    Thermography is a nondestructive testing (NDT) technique based on the principle that two dissimilar materials, i.e., possessing different thermo-physical properties, would produce two distinctive thermal signatures that can be revealed by an infrared sensor, such as a thermal camera. The fields of NDT applications are expanding from classical building or electronic components monitoring to more recent ones such as inspection of artworks or composite materials. Furthermore, thermography can be conveniently used as a didactic tool for physics education in universities given that it provides the possibility of visualizing fundamental principles, such as thermal physics and mechanics among others.

  18. Non-destructive Evaluation of Compound Semiconductor Thin-Film Solar Cells by Photothermal Beam Deflection Technique

    NASA Astrophysics Data System (ADS)

    Warrier, Anita R.; Sebastian, Tina; Kartha, C. Sudha; Vijayakumar, K. P.

    2015-01-01

    In this paper, it is demonstrated that the photothermal beam deflection technique can be used for measuring the series resistance, optimum load resistance, and conversion efficiency of thin-film solar cells. This technique is also used for determining the carrier transport properties of an absorber and window layer of -based solar cells during different stages of cell fabrication. Transport properties such as the carrier mobility, lifetime, and surface recombination velocity of the individual absorber and window layer are shown to influence the open-circuit voltage and short-circuit current of the final photovoltaic device. The cell parameters measured using the photothermal technique agree well with the electrical measurements. The principle of the technique is explained on the basis of the "mirage effect" and maximum power transfer theorem.

  19. Neutron Resonance Transmission Analysis (NRTA): A Nondestructive Assay Technique for the Next Generation Safeguards Initiative’s Plutonium Assay Challenge

    SciTech Connect

    J. W. Sterbentz; D. L. Chichester

    2010-12-01

    This is an end-of-year report for a project funded by the National Nuclear Security Administration's Office of Nuclear Safeguards (NA-241). The goal of this project is to investigate the feasibility of using Neutron Resonance Transmission Analysis (NRTA) to assay plutonium in commercial light-water-reactor spent fuel. This project is part of a larger research effort within the Next-Generation Safeguards Initiative (NGSI) to evaluate methods for assaying plutonium in spent fuel, the Plutonium Assay Challenge. The first-year goals for this project were modest and included: 1) developing a zero-order MCNP model for the NRTA technique, simulating data results presented in the literature, 2) completing a preliminary set of studies investigating important design and performance characteristics for the NRTA measurement technique, and 3) documentation of this work in an end of the year report (this report). Research teams at Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), Pacific Northwest National Laboratory (PNNL), and at several universities are also working to investigate plutonium assay methods for spent-fuel safeguards. While the NRTA technique is well proven in the scientific literature for assaying individual spent fuel pins, it is a newcomer to the current NGSI efforts studying Pu assay method techniques having just started in March 2010; several analytical techniques have been under investigation within this program for two to three years or more. This report summarizes a nine month period of work.

  20. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Twelfth quarterly report, July-September 1980

    SciTech Connect

    Not Available

    1980-10-01

    Detection of electric-discharge machined notches in a silicon carbide tube by an ultrasonic bore-side probe under microcomputer control has been demonstrated. Use of the reflection mode has been shown to enhance the sensitivity of flaw detection with an acoustic microscope. In this configuration, the transducer and laser-scanned coverslip are both on the tube outer surface, eliminating the need to fill the tube with water. A conceptual design is presented for inspecting tubes up to seven feet long in both through-transmission and reflection-mode configurations. A comparison of NDE techniques for ceramic butt joints showed holographic interferometry to be generally better than dye-penetrant, radiographic, or ultrasonic techniques for characterizing a crack-like inner-wall defect. Pitch-catch and pulse-echo ultrasonic techniques also indicated the presence of an anomaly in the region identified as flawed via holography, while radiographic and penetrant-testing results were ambiguous.

  1. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Third annual report, October 1979-September 1980

    SciTech Connect

    Kupperman, D S; Yuhas, D; Sciammarella, C; Caines, M J; Winiecki, A

    1980-12-01

    The goals of the present program are not only to develop hardware and procedures for efficiently inspecting ceramic heat-exchanger components in conventional ways, but also to develop advanced NDE techniques that will allow effective failure prediction. The main objectives in FY 1980 have been to (a) develop a computer-interfaced ultrasonic bore-side probe for preservice and in-service inspection, (b) develop and assess techniques for inspection of SiC tubing by acoustic microscopy, and (c) carry out preliminary tests to compare ultrasonic, holographic, and infrared techniques with more conventional dye-penetrant and radiographic methods for inspection of butt joints in ceramic tubes. Circumferential notches, 125 ..mu..m deep x 250 ..mu..m long, on the inner and outer surfaces of sintered and siliconized SiC tubes were successfully detected with an ultrasonic bore-side probe. The acoustic microscope was modified to handle 30- as well as 100-MHz sound waves, since the lower-frequency waves give better penetration of Sic tube walls. The modification decreased the acoustic noise. The ability to detect a notch only 250 x 125 x 75 ..mu..m in size was demonstrated. Efforts to examine a butt joint with dye-penetrant, radiographic, ultrasonic, and holographic-interferometry techniques revealed that while holography seemed to identify more clearly the presence of a crack-like inner surface flaw, ultrasonic pulse-echo and pitch-catch techniques at 22 MHz also indicated the presence of an anomaly; the ultrasonic and holographic results agreed with regard to angular location of the flaw.

  2. Defects detection and non-destructive testing (NDT) techniques in paintings: a unified approach through measurements of deformation

    NASA Astrophysics Data System (ADS)

    Sfarra, S.; Ibarra-Castanedo, C.; Ambrosini, D.; Paoletti, D.; Bendada, A.; Maldague, X.

    2013-05-01

    The present study is focused on two topics. The first one is a mathematical model, useful to understand the deformation of paintings, which uses straining devices, adjustable and micrometrically controlled via a pin supported in a hollow cylinder. Strains were analyzed by holographic interferometry (HI) technique using an appropriate frame. The second one concerns the need to improve the conservator's knowledge about the defect's detection and defect's propagation in acrylic painting characterized of underdrawings and pentimenti. To fulfill this task, a sample was manufactured to clarify the several uncertainties inherent the influence of external factors on their conservation. Subsurface anomalies were also retrieved by near-infrared reflectography (NIRR) and transmittography (NIRT) techniques, using LED lamps and several narrow-band filters mounted on a CMOS camera, working at different wavelengths each other and in combination with UV imaging. In addition, a sponge glued on the rear side of the canvas was impregnated with a precise amount of water by means of a syringe to verify the "stretcher effect" by the digital speckle photography (DSP) technique (using MatPIV). The same effect also affects the sharp transition of the canvas at the stretcher's edge. In this case, a possible mechanism is a direct mechanical contact between stretcher and canvas that was investigated by HI technique. Finally, advanced algorithms applied to the square heating thermography (SHT) data were very useful to detect three Mylar® inserts simulating different type of defects. These fabricated defects were also identified by optical techniques, while the visual inspection was the only one capable of detecting a biological damage.

  3. Several flow visualization and survey techniques developed recently in HARI

    NASA Astrophysics Data System (ADS)

    Fan, Jiechuan; Zhang, Xiaodi; Helian, Huizheng; Zhao, Dong

    1992-12-01

    This paper depicts three flow visualization and survey techniques developed recently at Harbin Aerodynamics Research Institute (HARI), i.e., color helium bubble flow visualization, combined light-sheet flow visualization, and computerized color graphic flow visualization. The principle, performance, and application of them are given in this paper.

  4. Nondestructive test of regenerative chambers

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Stauffis, R.; Wood, R.

    1972-01-01

    Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures.

  5. Development of a Nondestructive Non-Contact Acousto-Thermal Evaluation Technique for Damage Detection in Materials (Preprint)

    DTIC Science & Technology

    2011-11-01

    examples investigate accumulation of plasticity in Ti-6Al-4V, detection of incipient thermal damage in polymer matrix composite plate, and detection and...system and to evaluate damage due to plasticity. Polymer matrix composite samples were used to demonstrate the capability of the NCATS technique to...b. Heat damage in polymer matrix composite When exposed to temperatures approaching or exceeding the glass transition temperature, the strength of

  6. Non-destructive evaluation techniques applied to the study of fatigue microcrack growth in steel alloys: Final report

    SciTech Connect

    London, B.; Yuce, H.; Nelson, D.

    1987-10-01

    In Part I of this study, an ultrasonic surface acoustic wave (SAW) technique was used to monitor the depth of surface fatigue microcracks in 300M steel as they grew. This technique also provided information on the stress which must be applied to cause the cracks to fully open. Values of crack opening stress obtained by scanning electron microscope (SEM) measurements of crack tip opening displacements were compared with values determined acoustically. Good agreement was obtained. 300M steel, heat treated to yield strength of 1737 MPa, was tested at two different zero-to-maximum tension stress levels. Effects of residual stresses produced by two different surface preparations on the growth of small cracks were studied. One preparation was electropolishings while the other was stress-relieving followed by diamond paste polishing. Fatigue microcrack growth rate agreed well with that of large cracks in electropolished specimens but, the presence of shallow compressive residual stresses in other specimens caused growth rates as much as an order of magnitude lower than in electropolished specimens. In Part II, four different microstructures of 4140 steel were investigated. Small fatigue crack behavior was monitored using a surface acoustic wave ultrasonic technique to accurately measure crack depth and crack closure stress. Cracks from 50 to 200 ..mu..m in depth in specially designed catilevered bending samples were investigated. 143 refs., 74 figs., 5 tabs.

  7. The 6-GHz multibeam maser survey - I. Techniques

    NASA Astrophysics Data System (ADS)

    Green, J. A.; Caswell, J. L.; Fuller, G. A.; Avison, A.; Breen, S. L.; Brooks, K.; Burton, M. G.; Chrysostomou, A.; Cox, J.; Diamond, P. J.; Ellingsen, S. P.; Gray, M. D.; Hoare, M. G.; Masheder, M. R. W.; McClure-Griffiths, N. M.; Pestalozzi, M.; Phillips, C.; Quinn, L.; Thompson, M. A.; Voronkov, M. A.; Walsh, A.; Ward-Thompson, D.; Wong-McSweeney, D.; Yates, J. A.; Cohen, R. J.

    2009-01-01

    A new seven-beam 6-7GHz receiver has been built to survey the Galaxy and the Magellanic Clouds for newly forming high-mass stars that are pinpointed by strong methanol maser emission at 6668MHz. The receiver was jointly constructed by Jodrell Bank Observatory (JBO) and the Australia Telescope National Facility (ATNF) and allows simultaneous coverage at 6668 and 6035MHz. It was successfully commissioned at Parkes in 2006 January and is now being used to conduct the Parkes-Jodrell multibeam maser survey of the Milky Way. This will be the first systematic survey of the entire Galactic plane for masers of not only 6668-MHz methanol, but also 6035-MHz excited-state hydroxyl. The survey is two orders of magnitude faster than most previous systematic surveys and has an rms noise level of ~0.17Jy. This paper describes the observational strategy, techniques and reduction procedures of the Galactic and Magellanic Cloud surveys, together with deeper, pointed, follow-up observations and complementary observations with other instruments. It also includes an estimate of the survey detection efficiency. The 111d of observations with the Parkes telescope have so far yielded >800 methanol sources, of which ~350 are new discoveries. The whole project will provide the first comprehensive Galaxy-wide catalogue of 6668-MHz and 6035-MHz masers.

  8. Development of a numerical experiment technique to solve inverse gamma-ray transport problems with application to nondestructive assay of nuclear waste barrels

    SciTech Connect

    Chang, C.J.; Anghaie, S.

    1998-03-01

    A numerical experimental technique is presented to find an optimum solution to an undetermined inverse gamma-ray transport problem involving the nondestructive assay of radionuclide inventory in a nuclear waste drum. The method introduced is an optimization scheme based on performing a large number of numerical simulations that account for the counting statistics, the nonuniformity of source distribution, and the heterogeneous density of the self-absorbing medium inside the waste drum. The simulation model uses forward projection and backward reconstruction algorithms. The forward projection algorithm uses randomly selected source distribution and a first-flight kernel method to calculate external detector responses. The backward reconstruction algorithm uses the conjugate gradient with nonnegative constraint or the maximum likelihood expectation maximum method to reconstruct the source distribution based on calculated detector responses. Total source activity is determined by summing the reconstructed activity of each computational grid. By conducting 10,000 numerical simulations, the error bound and the associated confidence level for the prediction of total source activity are determined. The accuracy and reliability of the simulation model are verified by performing a series of experiments in a 208-{ell} waste barrel. Density heterogeneity is simulated by using different materials distributed in 37 egg-crate-type compartments simulating a vertical segment of the barrel. Four orthogonal detector positions are used to measure the emerging radiation field from the distributed source. Results of the performed experiments are in full agreement with the estimated error and the confidence level, which are predicted by the simulation model.

  9. Influence of porosity and relative humidity on consolidation of dolostone with calcium hydroxide nanoparticles: Effectiveness assessment with non-destructive techniques

    SciTech Connect

    Lopez-Arce, P.; Gomez-Villalba, L.S.; Pinho, L.; Fernandez-Valle, M.E.; Alvarez de Buergo, M.; Fort, R.

    2010-02-15

    Slaked lime (Ca(OH){sub 2}) nanoparticles were exposed at 33% and 75% relative humidity (RH) to consolidate dolostone samples used in historical buildings. Non-destructive techniques (NDT) were applied to determine the chemical, morphological, physical and hydric properties of the stone samples, before and after 20 days treatment. Morphological and mineralogical characterisation of the nanoparticles was performed. 75% RH favors the consolidation process studied under Environmental Scanning Electron Microscopy (ESEM-EDS), spectrophotometry, capillarity, water absorption under vacuum, ultrasound velocity, Nuclear Magnetic Resonance (imaging and relaxometry) and Optical Surface Roughness analyses. At 75% RH the nanoparticles fill the pores and inter-crystalline dolomite grain contacts but do not favor calcite re-crystallization as it occurs at 33% RH. The ESEM, XRD and TEM analyses under 75% RH reveal the fast transformation of portlandite (Ca(OH){sub 2}) into vaterite (CaCO{sub 3}), monohydrocalcite (CaCO{sub 3} . H{sub 2}O) and calcite (CaCO{sub 3}), and eventually the physical and hydric properties of the stones significantly improve. New insights are provided for the assessment of consolidation effectiveness of porous carbonate stones with calcium hydroxide nanoparticles under optimum RH conditions combining several NDT.

  10. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Eleventh quarterly report, April-June 1980

    SciTech Connect

    Not Available

    1980-08-01

    One of the problems associated with ultrasonic inspection of silicon carbide tubes from the bore side, for wall-thickness measurements or detection of laminar flaws, is the mode conversion of nominally normal-incidence longitudinal waves to shear waves. Under the right circumstances the shear wave can be detected by the transducer after it converts back to a longitudinal wave, and can be confused with a legitimate flaw signal. This phenomenon occurs because of the sharp curvature of the tube and the width of the ultrasonic beam. The effect is discussed in some detail in the present report; reducing the width of the ultrasonic beam to approx. 1 mm is shown to virtually eliminate the problem while not reducing the signal amplitude of the backwall echoes significantly (i.e., by > 5 dB). Infrared techniques have been applied to inspection of glass-adhesive overlap joints in silicon carbide tubes. The results suggest that infrared techniques may be employed successfully in characterizing ceramic overlap joints through observation of heat-flow patterns. Results of previous efforts had led to the conclusion that holographic interferometry, although sensitive to surface flaws, would be difficult to use as a general inspection method for ceramic materials. This technique needs to be reassessed with respect to ceramic joints for two reasons. One is that the irregular geometry of many joints makes ultrasonic signal interpretation difficult, but leaves open the possibility of detecting flaws indirectly by looking for regions of high strain. The other reason for a new look at holography is that the introduction of a television camera and videotape system has made the production and evaluation of holographic interferograms much easier.

  11. A new, non-destructive, real-time measurement technique of the surface area of aerogel during synthesis

    NASA Astrophysics Data System (ADS)

    Shen, Yang; Lee, Jeongseop A.; Halperin, W. P.

    We have developed a new method of measuring surface area of silica aerogel during the synthesis stage using a standard pulsed NMR setup. The applicability of this method can be extended to a much broader type of chemical reactions yielding a rigid porous condensate whose surface relaxation rate differs substantially from its surrounding liquids. The number of various chemical species involved in the reaction poses little to no limitation to its applicability owing to the physics in the fast exchange limit. This is the main distinguishing feature from a conventional NMR or infrared spectroscopy method in which individual chemical bondings from various reaction intermediaries are tracked in time which is often difficult if not impossible due to complex reactions. The result from this technique yields a surface area that is analogous to the result from a well-established BET (Brunauer-Emmett-Teller) technique, but without the need for extraction or supercritical extraction of the porous medium. This work was supported by the DOE BES under grants No. DE-FG02-05ER46248.

  12. Unshielded and Shielded Facility Nondestructive Inspection (NDI) Radiation Protection Survey for F.S. Gabreski ANGB, NY

    DTIC Science & Technology

    2013-11-06

    an area controlled by the NDI section and where workers have completed ALARA training. bMax Dose Estimate for 1 h = (Net Reading in mR/h...completed ALARA training. bMax Dose Estimate for 1 h = (Net Reading in mR/h)*[Exposure Duration (h)]. cAnnual Dose Estimate = (Net Reading (mR/h...RSO provided ALARA training (T.O. 33B-1-1, 6.8.2.1) 3. Ensure personnel are removed during exposures 4. Survey

  13. A survey of visual preprocessing and shape representation techniques

    NASA Technical Reports Server (NTRS)

    Olshausen, Bruno A.

    1988-01-01

    Many recent theories and methods proposed for visual preprocessing and shape representation are summarized. The survey brings together research from the fields of biology, psychology, computer science, electrical engineering, and most recently, neural networks. It was motivated by the need to preprocess images for a sparse distributed memory (SDM), but the techniques presented may also prove useful for applying other associative memories to visual pattern recognition. The material of this survey is divided into three sections: an overview of biological visual processing; methods of preprocessing (extracting parts of shape, texture, motion, and depth); and shape representation and recognition (form invariance, primitives and structural descriptions, and theories of attention).

  14. Reef Fish Survey Techniques: Assessing the Potential for Standardizing Methodologies

    PubMed Central

    Caldwell, Zachary R.; Zgliczynski, Brian J.; Williams, Gareth J.; Sandin, Stuart A.

    2016-01-01

    Dramatic changes in populations of fishes living on coral reefs have been documented globally and, in response, the research community has initiated efforts to assess and monitor reef fish assemblages. A variety of visual census techniques are employed, however results are often incomparable due to differential methodological performance. Although comparability of data may promote improved assessment of fish populations, and thus management of often critically important nearshore fisheries, to date no standardized and agreed-upon survey method has emerged. This study describes the use of methods across the research community and identifies potential drivers of method selection. An online survey was distributed to researchers from academic, governmental, and non-governmental organizations internationally. Although many methods were identified, 89% of survey-based projects employed one of three methods–belt transect, stationary point count, and some variation of the timed swim method. The selection of survey method was independent of the research design (i.e., assessment goal) and region of study, but was related to the researcher’s home institution. While some researchers expressed willingness to modify their current survey protocols to more standardized protocols (76%), their willingness decreased when methodologies were tied to long-term datasets spanning five or more years. Willingness to modify current methodologies was also less common among academic researchers than resource managers. By understanding both the current application of methods and the reported motivations for method selection, we hope to focus discussions towards increasing the comparability of quantitative reef fish survey data. PMID:27111085

  15. Study by non-destructive technique of gilding coat of arms of the Real Alcázar of Seville, Spain

    NASA Astrophysics Data System (ADS)

    Robador, M. D.; Pérez-Rodriguez, J. L.; Muñoz-García, A.; Garófano, I.; Garrote, M. A.; Odriozola, C.; Durán, A.

    2012-04-01

    The Real Alcazar of Seville is a building inscribed in the World Heritage List, being the most ancient Real Palace in Europe still in use. It was built over roman buildings, from the XI century to our days, exceptional buildings and gardens of the highest architectonical, cultural and historic value. High value wall paintings of different periods are located in different places all over the palace. In one of its chamber - the King's bedroom - golden medallions that represent the coat of arms of Leon and Castilla Kingdom appear decorating its walls. The objective of this work was the study of the materials employed in the manufacture of these coats by portable and non-destructive techniques: X-ray diffraction (XDR) and X-ray fluorescence (XRF) and Raman spectroscopy. The support used for gilding was also studied using conventional techniques such as: powder X-ray diffraction (powder XRD), thermal analysis (DTA-TG) and FT-IR spectroscopy. The results obtained by portable XRD, XRF and Raman spectroscopy showed that the polychrome was carried out with gold in all samples studied. Other elements such as silver and cooper were also found in minor proportion. XRF allowed the quantification of the different metal (average composition: Au 79.5 %, Ag 8.1 %, Cu 5 %). There were various ways of adhering the golden leaf to the surface, but for large areas a bole mix of fine earth was typical. For other ornamentations, technique based on an aqueous medium and brushed onto the part to be gilded was used an. For panel and wall paintings, however, oil mordant was commonly used. In our study the gold was adhered to the surface using oil mordant. The powder XRD of the support showed the presence of gypsum and small proportion of anhydrite. However, calcium carbonate was not detected due to low proportion and low diffraction intensity of the mineral. The DTA-TG study confirms the presence of calcite (less than 5%). This technique also revealed the presence of organic compounds (oil

  16. Nondestructive Evaluation for Aerospace Composites

    NASA Technical Reports Server (NTRS)

    Leckey, Cara; Cramer, Elliott; Perey, Daniel

    2015-01-01

    Nondestructive evaluation (NDE) techniques are important for enabling NASA's missions in space exploration and aeronautics. The expanded and continued use of composite materials for aerospace components and vehicles leads to a need for advanced NDE techniques capable of quantitatively characterizing damage in composites. Quantitative damage detection techniques help to ensure safety, reliability and durability of space and aeronautic vehicles. This presentation will give a broad outline of NASA's range of technical work and an overview of the NDE research performed in the Nondestructive Evaluation Sciences Branch at NASA Langley Research Center. The presentation will focus on ongoing research in the development of NDE techniques for composite materials and structures, including development of automated data processing tools to turn NDE data into quantitative location and sizing results. Composites focused NDE research in the areas of ultrasonics, thermography, X-ray computed tomography, and NDE modeling will be discussed.

  17. Surveying co-located space geodesy techniques for ITRF computation

    NASA Astrophysics Data System (ADS)

    Sarti, P.; Sillard, P.; Vittuari, L.

    2003-04-01

    We present a comprehensive operational methodology, based on classical geodesy triangulation and trilateration, that allows the determination of reference points of the five space geodesy techniques used in ITRF computation (i.e.: DORIS, GPS, LLR, SLR, VLBI). Most of the times, for a single technique, the reference point is not accessible and measurable directly. Likewise, no mechanically determined ex-center with respect to an external and measurable point is usually given. In these cases, it is not possible to directly measure the sought reference points and it is even less straightforward to obtain the statistical information relating these points for different techniques. We outline the most general practical surveying methodology that permits to recover the reference points of the different techniques regardless of their physical materialization. We also give a detailed analytical approach for less straightforward cases (e.g.: non geodetic VLBI antennae and SLR/LLR systems). We stress the importance of surveying instrumentation and procedure in achieving the best possible results and outline the impact of the information retrieved with our method in ITRF computation. In particular, we will give numerical examples of computation of the reference point of VLBI antennae (Ny Aalesund and Medicina) and the ex-centre vector computation linking co-located VLBI and GPS techniques in Medicina (Italy). A special attention was paid to the rigorous derivation of statistical elements. They will be presented in an other presentation.

  18. The Importance of Local Surveys for Tying Techniques Together

    NASA Technical Reports Server (NTRS)

    Long, James L.; Bosworth, John M.

    2000-01-01

    The synergistic benefits of combining observations from multiple space geodesy techniques located at a site are a main reason behind the proposal for the establishment of the International Space Geodetic and Gravimetric Network (ISGN). However, the full benefits of inter-comparison are only realized when the spatial relationships between the different space geodetic systems are accurately determined. These spatial relationships are best determined and documented by developing a local reference network of stable ground monuments and conducting periodic surveys to tie together the reference points (for example: the intersection of rotation axes of a VLBI antenna) of the space geodetic systems and the ground monument network. The data obtained from local surveys is vital to helping understand any systematic errors within an individual technique and to helping identify any local movement or deformation of the space geodetic systems over time.

  19. Integrated Surveying Techniques for Sensitive Areas: San Felice Sul Panaro

    NASA Astrophysics Data System (ADS)

    Ballarin, M.; Buttolo, V.; Guerra, F.; Vernier, P.

    2013-07-01

    The last few years have marked an exponential growth in the use of electronic and computing technologies that opened new possibilities and new scenarios in the Geomatic field. This evolution of tools and methods has led to new ways of approaching survey. For what concerns architecture, the new tools for survey acquisition and 3D modelling allow the representation of an object through a digital model, combining the visual potentials of images, normally used for documentation, with the precision of a metric survey. This research focuses on the application of these new technologies and methodologies on sensitive areas, such as portions of the cities affected by earthquakes. In this field the survey is intended to provide a useful support for other structural analysis, in conservation as well as for restoration studies. However, survey in architecture is still a very complex operation both from a methodological and a practical point of view: it requires a critical interpretation of the artefacts and a deep knowledge of the existing techniques and technologies, which often are very different but need to be integrated within a single general framework. This paper describes the first results of the survey conducted on the church of San Geminiano in San Felice sul Panaro (Modena). Here, different tools and methods were used, in order to create a new system that integrates the most recent and cutting-edge technologies in the Geomatic field. The methodologies used were laser scanning, UAV photogrammetry and topography for the definition of the reference system. The present work will focus on the data acquisition and processing whit these techniques and their integration.

  20. Non-destructive soil amendment application techniques on heavy metal-contaminated grassland: Success and long-term immobilising efficiency.

    PubMed

    Friesl-Hanl, Wolfgang; Platzer, Klaus; Riesing, Johann; Horak, Othmar; Waldner, Georg; Watzinger, Andrea; Gerzabek, Martin H

    2017-01-15

    Extensive contamination of grassland with cadmium (Cd), lead (Pb) and zinc (Zn) is a typical problem close to Pb/Zn smelter sites. The entry of Cd or Pb into the food chain is very likely, as are toxicity effects of Zn in plants. Previous promising results from pot and field experiments showed the high potential of using amendments for immobilisation to reduce metal input into the food chain via crops grown on smelter-contaminated soils at Arnoldstein (Austria) (Friesl et al., 2006). The aim of this study was to find a practical solution for large-scale contaminations in hilly regions that avoids erosion. Field application of amendments without destroying the vegetation cover (grassland) involved two approaches: (a) slurrying (Slu) the amendments into cut gaps in the vegetation cover and (b) injecting (Inj) the amendments through the vegetation cover. Here, we investigate the immobilising and long-term efficiency of treatments [gravel sludge (2.5%) + red mud (0.5%) (GS + RM)]. Risk assessment was based on soil, plant and water samples taken over a period of 10 years. Ammonium-nitrate-extractable Cd was reduced up to 50%, Pb up to 90%, and Zn over 90%. Plant uptake into the grass mixture and narrow leaf plantain was significantly reduced for Cd, Pb, and Zn. Harvesting early in vegetation period can further reduce uptake and meet the threshold for fodder crops. The reduction of these elements in the seepage water in 24 samplings within these 10 years reached 40%, 45% and 50%, respectively. Immobilisation increased microbial biomass and decreased human bioaccessibility for Pb. Our investigation of the long-term efficiency of GS + RM in all treatments shows that the Slu and Inj amendment application techniques have promising potential as a realistic and practical method for extensively contaminated hilly land. Slurrying performed best. We conclude that grassland remediation methods involving tillage are counterproductive from the viewpoint of bioaccessibility

  1. Digital Survey Techniques for the Documentation of Wooden Shipwrecks

    NASA Astrophysics Data System (ADS)

    Costa, E.; Balletti, C.; Beltrame, C.; Guerra, F.; Vernier, P.

    2016-06-01

    Nowadays, researchers widely employ the acquisition of point clouds as one of the principal type of documentation for cultural heritage. In this paper, different digital survey techniques are employed to document a wooden ancient shipwreck, a particular and difficult kind of archaeological finding due to its material characteristics. The instability of wood and the high costs of restoration do not always offer the opportunity of recovering and showing the hull to researchers and public and three-dimensional surveys are fundamental to document the original conditions of the wood. The precarious conditions of this material in contact with air could modify the structure and the size of the boat, requiring a fast and accurate recording technique. The collaboration between Ca' Foscari University and the Laboratory of Photogrammetry of Iuav University of Venice has given the possibility to demonstrate the utility of these technology. We have surveyed a sewn boat of Roman age through multi-image photogrammetry and laser scanner. Point clouds were compared and a residual analysis was done, to verify the characteristics and the opportunity of the two techniques, both of them have allowed obtaining a very precise documentation from a metrical point of view.

  2. Testing Different Survey Techniques to Model Architectonic Narrow Spaces

    NASA Astrophysics Data System (ADS)

    Mandelli, A.; Fassi, F.; Perfetti, L.; Polari, C.

    2017-08-01

    In the architectural survey field, there has been the spread of a vast number of automated techniques. However, it is important to underline the gap that exists between the technical specification sheet of a particular instrument and its usability, accuracy and level of automation reachable in real cases scenario, especially speaking about Cultural Heritage (CH) field. In fact, even if the technical specifications (range, accuracy and field of view) are known for each instrument, their functioning and features are influenced by the environment, shape and materials of the object. The results depend more on how techniques are employed than the nominal specifications of the instruments. The aim of this article is to evaluate the real usability, for the 1:50 architectonic restitution scale, of common and not so common survey techniques applied to the complex scenario of dark, intricate and narrow spaces such as service areas, corridors and stairs of Milan's cathedral indoors. Tests have shown that the quality of the results is strongly affected by side-issues like the impossibility of following the theoretical ideal methodology when survey such spaces. The tested instruments are: the laser scanner Leica C10, the GeoSLAM ZEB1, the DOT DPI 8 and two photogrammetric setups, a full frame camera with a fisheye lens and the NCTech iSTAR, a panoramic camera. Each instrument presents advantages and limits concerning both the sensors themselves and the acquisition phase.

  3. A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique and Three Types of Gamma-ray Detectors

    SciTech Connect

    Jorge Navarro; Rahmat Aryaeinejad,; David W. Nigg

    2011-05-01

    A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique1 Rahmat Aryaeinejad, Jorge Navarro, and David W Nigg Idaho National Laboratory Abstract Effective and efficient Advanced Test Reactor (ATR) fuel management require state of the art core modeling tools. These new tools will need isotopic and burnup validation data before they are put into production. To create isotopic, burn up validation libraries and to determine the setup for permanent fuel scanner system a feasibility study was perform. The study consisted in measuring short and long cooling time fuel elements at the ATR canal. Three gamma spectroscopy detectors (HPGe, LaBr3, and HPXe) and two system configurations (above and under water) were used in the feasibility study. The first stage of the study was to investigate which detector and system configuration would be better suited for different scenarios. The second stage of the feasibility study was to create burnup and cooling time calibrations using experimental isotopic data collected and ORIGEN 2.2 burnup data. The results of the study establish that a better spectra resolution is achieve with an above the water configuration and that three detectors can be used in the permanent fuel scanner system for different situations. In addition it was conclude that a number of isotopic ratios and absolute measurements could be used to predict ATR fuel burnup and cooling times. 1This work was supported by the U.S. Depart¬ment of Energy (DOE) under Battelle Energy Alliance, LLC Contract No. DE-AC07-05ID14517.

  4. A Survey of Architectural Techniques for Near-Threshold Computing

    SciTech Connect

    Mittal, Sparsh

    2015-12-28

    Energy efficiency has now become the primary obstacle in scaling the performance of all classes of computing systems. In low-voltage computing and specifically, near-threshold voltage computing (NTC), which involves operating the transistor very close to and yet above its threshold voltage, holds the promise of providing many-fold improvement in energy efficiency. However, use of NTC also presents several challenges such as increased parametric variation, failure rate and performance loss etc. Our paper surveys several re- cent techniques which aim to offset these challenges for fully leveraging the potential of NTC. By classifying these techniques along several dimensions, we also highlight their similarities and differences. Ultimately, we hope that this paper will provide insights into state-of-art NTC techniques to researchers and system-designers and inspire further research in this field.

  5. Power Management Techniques for Data Centers: A Survey

    SciTech Connect

    Mittal, Sparsh

    2014-07-01

    With growing use of internet and exponential growth in amount of data to be stored and processed (known as ``big data''), the size of data centers has greatly increased. This, however, has resulted in significant increase in the power consumption of the data centers. For this reason, managing power consumption of data centers has become essential. In this paper, we highlight the need of achieving energy efficiency in data centers and survey several recent architectural techniques designed for power management of data centers. We also present a classification of these techniques based on their characteristics. This paper aims to provide insights into the techniques for improving energy efficiency of data centers and encourage the designers to invent novel solutions for managing the large power dissipation of data centers.

  6. A Survey of Architectural Techniques for Near-Threshold Computing

    DOE PAGES

    Mittal, Sparsh

    2015-12-28

    Energy efficiency has now become the primary obstacle in scaling the performance of all classes of computing systems. In low-voltage computing and specifically, near-threshold voltage computing (NTC), which involves operating the transistor very close to and yet above its threshold voltage, holds the promise of providing many-fold improvement in energy efficiency. However, use of NTC also presents several challenges such as increased parametric variation, failure rate and performance loss etc. Our paper surveys several re- cent techniques which aim to offset these challenges for fully leveraging the potential of NTC. By classifying these techniques along several dimensions, we also highlightmore » their similarities and differences. Ultimately, we hope that this paper will provide insights into state-of-art NTC techniques to researchers and system-designers and inspire further research in this field.« less

  7. Literature survey of heat transfer enhancement techniques in refrigeration applications

    SciTech Connect

    Jensen, M.K.; Shome, B.

    1994-05-01

    A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

  8. Survey of Product-line Verification and Validation Techniques

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn

    2007-01-01

    This report presents the results from the first task of the SARP Center Initiative, 'Product Line Verification of Safety-Critical Software.' Task 1 is a literature survey of available techniques for product line verification and validation. Section 1 of the report provides an introduction to product lines and motivates the survey of verification techniques. It describes what is reused in product-line engineering and explains the goal of verifiable conformance of the developed system to its product-line specifications. Section 2 of the report describes six lifecycle steps in product-line verification and validation. This description is based on, and refers to, the best practices extracted from the readings. It ends with a list of verification challenges for NASA product lines (2.7) and verification enablers for NASA product lines (2.8) derived from the survey. Section 3 provides resource lists of related conferences, workshops, industrial and defense industry experiences and case studies of product lines, and academic/industrial consortiums. Section 4 is a bibliography of papers and tutorials with annotated entries for relevant papers not previously discussed in sections 2 or 3.

  9. Discrete square root filtering - A survey of current techniques.

    NASA Technical Reports Server (NTRS)

    Kaminskii, P. G.; Bryson, A. E., Jr.; Schmidt, S. F.

    1971-01-01

    Current techniques in square root filtering are surveyed and related by applying a duality association. Four efficient square root implementations are suggested, and compared with three common conventional implementations in terms of computational complexity and precision. It is shown that the square root computational burden should not exceed the conventional by more than 50% in most practical problems. An examination of numerical conditioning predicts that the square root approach can yield twice the effective precision of the conventional filter in ill-conditioned problems. This prediction is verified in two examples.

  10. A new survey technique at hard X-rays

    NASA Astrophysics Data System (ADS)

    Bottacini, Eugenio; Ajello, Marco

    2013-06-01

    In the view of the so-called Active Galactic Nuclei (AGN) unified model, the nuclear activity is powered by a super-massive black hole (SMBH) at the center of a galaxy. An optically thick gas-dust structure surrounding the SMBH absorbs efficiently the nuclear radiation. Current surveys of the INTEGRAL Soft-Gamma Ray Imager (IBIS/ISGRI) and of the Burst Alert Telescope (BAT) on board the Swift satellite have proven to be a powerful technique in detecting AGNs at soft gamma-ray energies. BAT and IBIS/ISGRI are coded-mask detectors having two major advantages: 1) they have a huge field of view, hence allowing to detect an large number of AGNs; 2) they operate at soft gamma-rays, hence collecting photons that are energetic enough to pierce efficiently through the gas-dust structure surrounding the SMBH. However, the sensitivity of coded-mask detectors is limited by heavy systematic uncertainties. Furthermore by design they block ˜50% of the incident photons causing an increase of statistical noise. This prevents the detection of the most absorbed AGNs. In this paper we will show that the BAT and the IBIS/ISGRI observations can be merged in order to produce a deep sky survey less susceptible to systematic and statistical noise. The survey of this virtual new mission extends over a wide sky area of 6200 deg2 sampling 113 sources. The scientific outcome from the study of the sample has been properly addressed to study the evolution of AGNs in the local Universe. Our results are compared to other missions and predictions on the results of the recently launched NuSTAR mission are made. We discuss the expected results when applying this survey to the entire extragalactic sky and first results of this survey on the Galactic center are shown.

  11. Importance of integrated results of different non-destructive techniques in order to evaluate defects in panel paintings: the contribution of infrared, optical and ultrasonic techniques

    NASA Astrophysics Data System (ADS)

    Sfarra, S.; Theodorakeas, P.; Ibarra-Castanedo, C.; Avdelidis, N. P.; Paoletti, A.; Paoletti, D.; Hrissagis, K.; Bendada, A.; Koui, M.; Maldague, X.

    2011-06-01

    The increasing deterioration of panel paintings can be due to physical processes that take place during exhibition or transit, or as a result of temperature and humidity fluctuations within a building, church or museum. In response to environmental alterations, a panel painting can expand or contract and a new equilibrium state is eventually reached. These adjustments though, are usually accompanied by a change in shape in order to accommodate to the new conditions. In this work, a holographic method for detecting detached regions and micro-cracks is described. Some of these defects are confirmed by Thermographic Signal Reconstruction (TSR) technique. In addition, Pulsed Phase Thermography (PPT) and Principal Component Thermography (PCT) allow to identify with greater contrast two artificial defects in Mylar which are crucial to understand the topic of interest: the discrimination between defect materials. Finally, traditional contact ultrasounds applications, are widely applied for the evaluation of the wood quality in several characterization procedures. Inspecting the specimen from the front side, the natural and artificial defects of the specimen are confirmed. Experimental results derived by the application of the integrated methods on an Italian panel painting reproduction, called The Angel specimen, are presented. The main advantages that these techniques can offer to the conservation and restoration of artworks are emphasized.

  12. Nondestructive characterization of pipeline materials

    NASA Astrophysics Data System (ADS)

    Engle, Brady J.; Smart, Lucinda J.; Bond, Leonard J.

    2015-03-01

    There is a growing need to quantitatively and nondestructively evaluate the strength and toughness properties of pipeline steels, particularly in aging pipeline infrastructure. These strength and toughness properties, namely yield strength, tensile strength, transition temperature, and toughness, are essential for determining the safe operating pressure of the pipelines. For some older pipelines crucial information can be unknown, which makes determining the pressure rating difficult. Current inspection techniques address some of these issues, but they are not comprehensive. This paper will briefly discuss current inspection techniques and relevant literature for relating nondestructive measurements to key strength and toughness properties. A project is in progress to provide new in-trench tools that will give strength properties without the need for sample removal and destructive testing. Preliminary experimental ultrasonic methods and measurements will be presented, including velocity, attenuation, and backscatter measurements.

  13. Digital holographic nondestructive testing of laminate composite

    NASA Astrophysics Data System (ADS)

    Karray, Mayssa; Christophe, Poilane; Gargouri, Mohamed; Picart, Pascal

    2016-09-01

    Optical digital holographic techniques can be used for nondestructive testing of materials. Digital holographic nondestructive testing essentially measures deformations on the surface of the object. However, there is sufficient sensitivity to detect subsurface and internal defects in metallic and composite specimens. We investigate and discuss the vibration analysis of laminated composite glass-epoxy using time averaging in digital Fresnel holography to visualize the modes of vibration and to test the integrity of the structures of studied materials.

  14. Using machine learning techniques to automate sky survey catalog generation

    NASA Technical Reports Server (NTRS)

    Fayyad, Usama M.; Roden, J. C.; Doyle, R. J.; Weir, Nicholas; Djorgovski, S. G.

    1993-01-01

    We describe the application of machine classification techniques to the development of an automated tool for the reduction of a large scientific data set. The 2nd Palomar Observatory Sky Survey provides comprehensive photographic coverage of the northern celestial hemisphere. The photographic plates are being digitized into images containing on the order of 10(exp 7) galaxies and 10(exp 8) stars. Since the size of this data set precludes manual analysis and classification of objects, our approach is to develop a software system which integrates independently developed techniques for image processing and data classification. Image processing routines are applied to identify and measure features of sky objects. Selected features are used to determine the classification of each object. GID3* and O-BTree, two inductive learning techniques, are used to automatically learn classification decision trees from examples. We describe the techniques used, the details of our specific application, and the initial encouraging results which indicate that our approach is well-suited to the problem. The benefits of the approach are increased data reduction throughput, consistency of classification, and the automated derivation of classification rules that will form an objective, examinable basis for classifying sky objects. Furthermore, astronomers will be freed from the tedium of an intensely visual task to pursue more challenging analysis and interpretation problems given automatically cataloged data.

  15. Integration of Geomatic Techniques for the Urban Cavity Survey

    NASA Astrophysics Data System (ADS)

    Deidda, M.; Sanna, G.

    2013-07-01

    Cagliari, county seat of Sardinia Region (Italy), situated in the southern part of the island, is characterized by a subsoil full of cavities. The excavations in fact, which lasted more than 4000 years, had a great development due also to the special geological characteristics of the city subsoil. The underground voids, which the city is rich in, belong to different classes such as hydraulic structures (aqueducts, cisterns, wells, etc.), settlement works (tunnels, bomb shelters, tombs etc.) and various works (quarries, natural caves, etc.). This paper describes the phases of the survey of a large cavity below a high-traffic square near the Faculty of Engineering in the city of Cagliari, where the research team works. The cave, which is part of a larger complex, is important because it was used in the thirteenth century (known as the Pisan age) as a stone quarry. There are traces of this activity that have to be protected. Moreover, during the last forty years the continuous crossover of vehicles cracked the roof of the cave compromising the stability of the entire area. Consequently a plan was developed to make the whole cavity safe and usable for visits. The study of the safety of the cave has involved different professionals among which geologists, engineers, constructors. The goal of the University of Cagliari geomatic team was to solve two problems: to obtain geometrical information about the void and correctly place the cave in the context of existing maps. The survey and the products, useful for the investigation of the technicians involved, had to comply with tolerances of 3 cm in the horizontal and 5 cm in the vertical component. The approach chosen for this purpose was to integrate different geomatic techniques. The cave was surveyed using a laser scanner (Faro Photon 80) in order to obtain a 3D model of the cave from which all the geometrical information was derived, while both classic topography and GPS techniques were used to include the cave in the

  16. Survey of Experts on Current Endothelial Keratoplasty Techniques

    PubMed Central

    Chamberlain, Winston; Austin, Ariana; Terry, Mark; Jeng, Bennie H; Rose-Nussbaumer, Jennifer

    2016-01-01

    Objective To survey cornea specialists’ opinions on different endothelial keratoplasty techniques and to gauge the perceived need for and utility of a randomized controlled trial (RCT) comparing them. Methods A short survey was distributed to a group of cornea specialists at the Endothelial Keratoplasty Group meeting at the American Academy of Ophthalmology meeting in November 2015. Results Thirty-three of 80 practicing surgeons present at the EKG meeting participated in the survey, yielding a response rate of 41%. Ninety-seven percent (n=32) of our respondents reported performing Descemet’s Stripping Endothelial Keratoplasty (DSEK) regularly, and 70% reported having performed Descemet’s Membrane Endothelial Keratoplasty (DMEK) at least once (n=23). While most respondents (n=26, 79%) thought there was at least some evidence that DMEK is superior to DSEK in terms of visual acuity, there was less certainty about comparing ultrathin-DSEK (UT-DSEK) to DMEK with 48% (n=16) thinking there was at least some evidence of DMEK’s superiority, 6% (n=2) thinking there was at least some evidence of UT-DSEK’s superiority, and 30% (n=10) unsure. Seventy-two percent (n=23) of respondents thought an RCT comparing visual acuity outcomes in UT-DSEK versus DMEK would be at least moderately beneficial, and 82% (n=27) reported they were at least moderately likely to change their EK technique based on the results of said RCT. Conclusion There is substantial interest in an RCT comparing visual acuity outcomes in UT-DSEK versus DMEK. PMID:28149669

  17. Quantitative optical techniques for dense sprays investigation: A survey

    NASA Astrophysics Data System (ADS)

    Coghe, A.; Cossali, G. E.

    2012-01-01

    The experimental study of dense sprays by optical techniques poses many challenges and no methods have proven to be completely reliable when accurate quantitative data are required, for example to validate breakup models and CFD simulations. The present survey is aimed to a critical analysis of optical techniques capable to provide quantitative and reliable data in dense sprays and to point out the conditions necessary to safely obtain such measurements. A single parameter, the optical depth, is proposed to quantify the concept of dense spray and to indicate when multiple scattering becomes predominant and could make the experimental results questionable. Many available optical techniques are divided into two categories: the "classical" ones, like PDA, LDV, PIV, etc., that work well in dilute sprays but show many limitations in dense sprays, and the "emerging" ones more suitable for dense sprays. Among the last ones, those considered more promising are discussed in detail. A number of significant applications are also presented and discussed to better clarify the nature of such complex problem and the feasibility of the new proposed approaches.

  18. Overview of nondestructive evaluation technologies

    SciTech Connect

    Thomas, G.

    1995-04-01

    The infrastructure in the US and the world is aging. There is an increasing awareness of the need to assess the severity of the damage occurring to the infrastructure. Limited resources preclude the replacement of all structures that need repairs or have exceeded their life times. Methods to assess the amount and severity of damage are crucial to implementing a systematic, cost effective approach to repair and/or replace the damaged structures. The challenges of inspecting aging structures without impairing their usefulness rely on a variety of technologies and techniques for nondestructive evaluation (NDE). This paper will briefly describe several nondestructive evaluation technologies that are required for inspecting a variety of systems and structures.

  19. Combined use of the non-destructive XRF and low energy micro-XRF techniques for the analysis of silvered nummi belonging to the Treasure of Misurata (Libya)

    NASA Astrophysics Data System (ADS)

    Romano, Francesco Paolo; Garraffo, Salvatore; Pappalardo, Lighea; Rizzo, Francesca

    2013-04-01

    Roman coinage underwent a severe debasement of silver during the time and the production of plated coins became a common practice for giving the impression of a high finesses of the alloy. In 294 AD, Diocletian introduced the nummus, manufactured with the same standard in all the mints by using an internal Cu-Sn-Pb-Ag core and presenting a thin silvered patina (about 2 micron) on its surface. The silver plating of the nummi have been investigated in the past and different methods have been suggested for its manufacturing (e.g. segregation during casting, chemical treatments, mercury-silvering). However, previous analyses were focused on few samples and, consequently, this technological issue remained unresolved. In the present work, the BSC-XRF (Beam Stability Controlled -XRF) and a LE-micro-XRF portable spectrometers developed at the LANDIS laboratory of IBAM-CNR and LNS-INFN in Catania (Italy), have been applied for the in-situ analysis of the silvered nummi belonging to the Misurata Treasure (Museum of Leptis Magna, El-Khomes, Libya). The treasure is composed of 108 thousand coins manufactured in 19 Imperial mints operating in the period 294-333 AD. In order to establish if, and at what extent, the mercury-silvering was used to produce the thin Ag-patina of the nummi, the non-destructive investigation was extended to 1050 well preserved coins. Measurements allowed to explore the presence of Hg and the Hg-Ag correlation at the coin surface. The portable BSC-XRF and the LE-micro XXRF techniques are suited to approach this study. A new version of the BSC-XRF spectrometer, consisting of a compact high-intensity x-ray tube (50 kV; 4 mA) coupled to a 80 mm2 SDD detector (138 eV @ 5.9 keV), was developed for the fast determination of mercury traces in a large number of coins (measurement time is 150 seconds; MDL for Hg is 100 ppm). The investigation allowed to identify the Imperial mints and the periods where the mercury-silvering were probably used. However the BSC

  20. Stabilizing the Carbon Marker During Surveying: An Innovative Technique.

    PubMed

    Pande, Neelam Abhay; Kulkarni, Sayali; Radke, Usha; Rathi, Akhil

    2014-12-01

    Dental surveyor has been defined as an instrument used to determine the relative parallelism of two or more surfaces of the teeth or other parts of the cast of a dental arch. Therefore the primary purpose of surveying is to identify the modifications of oral structures that are necessary to fabricate a removable partial denture that will have a successful prognosis. It is the modification of tooth surfaces to accommodate placement of the component parts of the partial denture in their designated ideal position on abutment teeth that facilitates this prognosis. Routinely, during marking the survey line, the carbon marker breaks many a times, as it is somehow brittle in structure, even after holding it in the metal sheath. This unnecessarily lengthens the working time of the operator as well as laboratory personnel. In the above mentioned new technique, the plastic refill sheath holds the carbon marker easily and securely. This serves the marking on the cast without breakage of carbon marker, thus saves the operator's time. The plastic refill sheath is easily available and economical.

  1. A survey of CPU-GPU heterogeneous computing techniques

    DOE PAGES

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-07-04

    As both CPU and GPU become employed in a wide range of applications, it has been acknowledged that both of these processing units (PUs) have their unique features and strengths and hence, CPU-GPU collaboration is inevitable to achieve high-performance computing. This has motivated significant amount of research on heterogeneous computing techniques, along with the design of CPU-GPU fused chips and petascale heterogeneous supercomputers. In this paper, we survey heterogeneous computing techniques (HCTs) such as workload-partitioning which enable utilizing both CPU and GPU to improve performance and/or energy efficiency. We review heterogeneous computing approaches at runtime, algorithm, programming, compiler and applicationmore » level. Further, we review both discrete and fused CPU-GPU systems; and discuss benchmark suites designed for evaluating heterogeneous computing systems (HCSs). Furthermore, we believe that this paper will provide insights into working and scope of applications of HCTs to researchers and motivate them to further harness the computational powers of CPUs and GPUs to achieve the goal of exascale performance.« less

  2. A survey of CPU-GPU heterogeneous computing techniques

    SciTech Connect

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-07-04

    As both CPU and GPU become employed in a wide range of applications, it has been acknowledged that both of these processing units (PUs) have their unique features and strengths and hence, CPU-GPU collaboration is inevitable to achieve high-performance computing. This has motivated significant amount of research on heterogeneous computing techniques, along with the design of CPU-GPU fused chips and petascale heterogeneous supercomputers. In this paper, we survey heterogeneous computing techniques (HCTs) such as workload-partitioning which enable utilizing both CPU and GPU to improve performance and/or energy efficiency. We review heterogeneous computing approaches at runtime, algorithm, programming, compiler and application level. Further, we review both discrete and fused CPU-GPU systems; and discuss benchmark suites designed for evaluating heterogeneous computing systems (HCSs). Furthermore, we believe that this paper will provide insights into working and scope of applications of HCTs to researchers and motivate them to further harness the computational powers of CPUs and GPUs to achieve the goal of exascale performance.

  3. An international survey about nail histology processing techniques.

    PubMed

    Wlodek, Christina; Lecerf, Pauline; Andre, Josette; Ruben, Beth S; de Berker, David

    2017-09-01

    There are limited data on nail histopathology techniques. The objective of this study was to examine nail histopathology techniques currently in use internationally. An online survey was sent to the European Nail Society and Council for Nail Disorders during 2015-2016. There were 57 respondents, from twenty countries comprising dermatologists, podiatrists and pathologists. Specimens were unmarked or marked using ink or a suture and fixed in 10% formalin, from 6 to 48 hours before embedding in paraffin wax (90% [17/19]), liquid nitrogen (frozen section, 1/19) and 2-hydroxyethylmethacrylate (plastic, 1/19). Nail softening was undertaken by 71% (17/24) of respondents for 6 to 48 hours using Mollifex Gurr (12.5%, 3/24), 10% potassium hydroxide solution (12.5%, 3/24) or 10% potassium thioglycolate cream (12.5%, 3/24). Section thickness was 4 to 9 µm (62.5%), using a steel microtome (92%,12/13) on glass slides (91.6%, 11/12). Hematoxylin and eosin (H&E) was routine for all biopsies and Periodic acid Schiff (PAS) for fungus. The favored stain for differentiating melanin and hemoglobin was Fontana-Masson (60%, 6/10). For pigmented lesions, Melan-A was always employed by all respondents (9/9). Nail histopathology processing has some small variations from normal skin processing. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Surveying and benchmarking techniques to analyse DNA gel fingerprint images.

    PubMed

    Heras, Jónathan; Domínguez, César; Mata, Eloy; Pascual, Vico

    2016-11-01

    DNA fingerprinting is a genetic typing technique that allows the analysis of the genomic relatedness between samples, and the comparison of DNA patterns. The analysis of DNA gel fingerprint images usually consists of five consecutive steps: image pre-processing, lane segmentation, band detection, normalization and fingerprint comparison. In this article, we firstly survey the main methods that have been applied in the literature in each of these stages. Secondly, we focus on lane-segmentation and band-detection algorithms-as they are the steps that usually require user-intervention-and detect the seven core algorithms used for both tasks. Subsequently, we present a benchmark that includes a data set of images, the gold standards associated with those images and the tools to measure the performance of lane-segmentation and band-detection algorithms. Finally, we implement the core algorithms used both for lane segmentation and band detection, and evaluate their performance using our benchmark. As a conclusion of that study, we obtain that the average profile algorithm is the best starting point for lane segmentation and band detection.

  5. Nondestructive Evaluation of a Graphite Aluminum Composite Space Radiator Panel

    DTIC Science & Technology

    1991-12-01

    techniques: ultrasound, x-ray, dye penetrant, and visual inspection. The results illustrate the importance of nondestructive evaluation ( NDE ) in the...importance of nondestructive evaluation ( NDE ) from the time the composite is fabricated through the time it is implemented into the spacecraft. These... NDE technologies will help detect external or internal irregularities (anomalies) at each increment of the fabrication and qualification testing of

  6. Non-destructive ripeness sensing by using proton NMR (Nuclear Magnetic Resonance)

    SciTech Connect

    Cho, Seong In; Krutz, G.W.; Stroshine, R.L. . Dept. of Agricultural Engineering); Bellon, V. , 34 - Montpellier )

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz). 7 refs., 4 figs.

  7. Non-destructive Ripeness Sensing by Using Proton NMR [Nuclear Magnetic Resonance

    DOE R&D Accomplishments Database

    Cho, Seong In; Krutz, G. W.; Stroshine, R. L.; Bellon, V.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz).

  8. Survey techniques developed to align stacked beamlines at CEBAF

    SciTech Connect

    Curtis, C.J.; Oren, W.; Tremblay, K.J.

    1994-04-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) in Newport News, Virginia is a new accelerator designed to produce 4 GeV 200 micro-amp continuous wave beams for nuclear physics research. It consists of two superconducting linacs each accelerating electrons by 400 MeV and linked by arcs allowing five pass recirculation. These linacs form the straight sections in a racetrack shaped accelerator contained in over 1.3 km of tunnel. The beam lines will consist of 42 superconducting accelerating cryomodules (in the linacs only), over 400 dipoles, 650 quadrupoles, and 100 sextupoles, most of the which are concentrated in the two arc sections of the machine. It is here that the single beam fine from the linacs is split into five beams of offering energy and transported to the opposite linac where it is recombined into a single beam to again pass through a linac and receive additional acceleration. These recirculation arcs are designed to maintain beam quality through a lattice which is achromatic, isochronous and whose length is equal to a multiple number of RF wavelengths. The short term relative alignment tolerances coupled with the beam fine design reflect the beam quality issues while absolute positioning determines the range of adjustment needed to match the RF phase in the linac segments. The alignment techniques which use a monumented control network as a reference, are designed to position stacked magnets and their support systems to these tolerances. Specialized procedures were tailored from existing hardware and software systems to address each phase or step of the alignment process. This allowed a relatively rapid expansion of alignment services at a new laboratory where surveying support was not seriously addressed until more then one third of the enclosure had been built.

  9. Superconducting techniques for gravity survey and inertial navigation

    SciTech Connect

    Chan, H.A.; Moody, M.V.; Paik, H.J.; Parke, J.W.

    1985-03-01

    Major improvements in sensitivity and drift can be made in inertial instruments by utilizing benign properties of materials available at liquid helium temperatures. We are developing a three-axis gravity gradiometer in which magnetic fields produced by persistent currents are modulated by motions of superconducting proof masses. Signals arising from both differential and common mode motions of the proof masses are detected by SQUIDs. The present design parameters give an intrinsic gravity gradient noise of 2 X 10/sup -12/ s/sup -2/ Hz /SUP -1/2/ , subject to improvements with new superconducting techniques under tests. A demonstration of such high sensitivity requires a very strict control of all error sources. The performance of our prototype gravity gradiometer when tested in a noisy terrestrial environment with its sensitive axis tilted at an angle of tan/sup -1/ 2 /SUP 1/2/ with respect to Earth's gravity is degraded to an error level of 7 X 10/sup -10/ s/sup -2/ Hz /SUP -1/2/ . In order to compensate for commonacceleration induced errors, we are also developing a six-axis superconducting accelerometer, based on a similar principle, which can detect the linear and angular acceleration vectors of the gradiometer platform simultaneously. Motion of a single, magnetically levitated, proof mass is monitored to resolve linear acceleration components to 4 X 10/sup -12/ m s/sup -2/ Hz /SUP -1/2/ and angular acceleration components to 3 X 10/sup -11/ rad s/sup -2/ Hz /SUP -1/2/ . This accelerometer, combined with the gradiometer, represents a gradiometer-aided inertial navigation/survey system.

  10. Millefiori glasswork technique in the Migration Period: Investigation of beads with the use of nondestructive X-ray fluorescence micro-analysis

    NASA Astrophysics Data System (ADS)

    Hložek, M.; Trojek, T.

    2015-11-01

    This article shows how a non-destructive X-ray fluorescence micro-analysis enabled us to describe the elemental composition and the production technology of a unique millefiori bead that was found in a burial ground in Kyjov (Hodonin district, Czech Republic) dating back to the Migration Period. This graveyard includes more than 250 graves belonging to the Germanic Lombard tribe that were carefully explored in 2010. Only a few Langobardic burial grounds have been revealed in the Moravia until now. This burial ground is therefore a remarkable find, to which particular attention has been paid. The main aim of our project was to provide a proper description of the production technology for the millefiori bead.

  11. Improved method of imaging defect in noncontact and nondestructive technique by high-intensity aerial burst ultrasonic wave and optical equipment

    NASA Astrophysics Data System (ADS)

    Osumi, Ayumu; Saito, Tatsunori; Ito, Youichi

    2015-07-01

    We propose a noncontact and nondestructive method of imaging by using high-intensity aerial ultrasonic waves and optical equipment. This method identifies defects in an imaged area by analysis of the velocity distribution of vibration on the surface of an object continuously irradiated by aerial ultrasonic waves. In a previous study, a related method was applied but could not exactly image the defect shape and size because the vibration mode at the target’s surface is generated by a continuous wave that depends on the boundary between the defective area and the defect-free area. By avoiding this problem, the proposed method allows exact imaging of the defect shape and size. In this report, we simulate results from the proposed underlying principle and conduct an experiment based on the proposed principle.

  12. Application of non-destructive impedance-based monitoring technique for cyclic fatigue evaluation of endodontic nickel-titanium rotary instruments.

    PubMed

    Chang, Yau-Zen; Liu, Mou-Chuan; Pai, Che-An; Lin, Chun-Li; Yen, Kuang-I

    2011-06-01

    This study investigates the application of non-destructive testing based on the impedance theory in the cyclic fatigue evaluation of endodontic Ni-Ti rotary instruments. Fifty Ni-Ti ProTaper instruments were divided into five groups (n=10 in Groups A to E). Groups A to D were subjected to cyclic fatigue within an artificial canal (Group E was the control group). The mean value of the total life limit (TLL), defined as the instrument being rotated until fracture occurred was found to be 104 s in Group A. Each rotary instrument in Groups B, C and D were rotated until the tested instruments reached 80% (84 s), 60% (62 s) and 40% (42 s) of the TLL. After fatigue testing, each rotary instrument was mounted onto a custom-developed non-destructive testing device to give the tip of the instrument a progressive sideways bend in four mutually perpendicular directions to measure the corresponding impedance value (including the resistance and the reactance). The results indicated that the impedance value showed the same trend as the resistance, implying that the impedance was primarily affected by the resistance. The impedance value for the instruments in the 80% and 60% TLL groups increased by about 6 mΩ (about 7.5%) more than that of the instruments in the intact and 40% TLL groups. The SEM analysis result showed that crack striations were only found at the tip of the thread on the cracked surface of the instrument, consistent with the impedance measurements that found the impedance value of the cracked surface to be significantly different from those in other surfaces. These findings indicate that the impedance value may represent an effective parameter for evaluating the micro-structural status of Ni-Ti rotary instruments subjected to fatigue loading.

  13. Nondestructive evaluation of structural ceramics

    NASA Technical Reports Server (NTRS)

    Klima, Stanley J.; Baaklini, George Y.; Abel, Phillip B.

    1987-01-01

    A review is presented on research and development of techniques for nondestructive evaluation and characterization of advanced ceramics for heat engine applications. Highlighted in this review are Lewis Research Center efforts in microfocus radiography, scanning laser acoustic microscopy (SLAM), scanning acoustic microscopy (SAM), scanning electron acoustic microscopy (SEAM), and photoacoustic microscopy (PAM). The techniques were evaluated by applying them to research samples of green and sintered silicon nitride and silicon carbide in the form of modulus-of-rupture bars containing seeded voids. Probabilities of detection of voids were determined for diameters as small as 20 microns for microfucus radiography, SLAM, and SAM. Strengths and limitations of the techniques for ceramic applications are identified. Application of ultrasonics for characterizing ceramic microstructures is also discussed.

  14. NONDESTRUCTIVE EVALUATION (NDE) OF DAMAGED STRUCTURAL CERAMICS

    SciTech Connect

    Brennan, R. E.; Green, W. H.; Sands, J. M.; Yu, J. H.

    2009-03-03

    A combination of destructive and nondestructive testing methods was utilized to evaluate the impact velocity and energy conditions that caused fracture in alumina structural ceramics. Drop tower testing was used for low velocity impact with a high mass indenter and fragment simulating projectile testing was used for high velocity impact with a low mass projectile. The damaged samples were nondestructively evaluated using digital radiography and ultrasound C-scan imaging. The bulk damage detected by these techniques was compared to surface damage observed by visual inspection.

  15. Surveying techniques with a solid-state magnetic multishot device

    SciTech Connect

    Thorogood, J.L. ); Knott, D.R. )

    1990-09-01

    An electronic magnetic multishot instrument was introduced in 1985 to overcome accuracy and reliability limitations associated with conventional photomechanical multishot systems. This paper describes the survey system and the instrument's performance capabilities. Our aim is to develop a tool-performance model for general application to the management of surveying operations. Accuracy is considered in two parts: sensor errors are considered in detail, and external effects on accuracy- e.g., axial misalignment, bottom-hole-assembly (BHA) deflection, geomagnetic influences, and drillstring-induced interference- are analyzed and quantified. The authors found that geomagnetic influences and drillstring-induced interference dominate the ultimate performance of all magnetic tools, particularly this electronic multishot instrument. This paper also describes in-hole referencing, a method of eliminating these errors that involves surveying the first part of an openhole section with a high-accuracy gyroscope and aligning data derived from subsequent magnetic surveys with it.

  16. AIRBORNE INERTIAL SURVEYING USING LASER TRACKING AND PROFILING TECHNIQUES.

    USGS Publications Warehouse

    Cyran, Edward J.; ,

    1986-01-01

    The U. S. Geological Survey through a contract with the Charles Stark Draper Laboratory has developed the Aerial Profiling of Terrain System. This is an airborne inertial surveying system designed to use a laser tracker to provide position and velocity updates, and a laser profiler to measure terrain elevations. The performance characteristics of the system are discussed with emphasis placed on the performance of the laser devices. The results of testing the system are summarized for both performance evaluation and applications.

  17. Survey of techniques used to preserve biological materials

    NASA Technical Reports Server (NTRS)

    Feinler, E. J.; Hubbard, R. W.

    1972-01-01

    The techniques used to preserve biological materials are documented and summarized. The report is presented in a handbook format that categorizes the most important preservation techniques available, and includes a representative sampling of the thousands of applications of these techniques to biological materials and organisms. Details of the information coverage and method of approach are outlined. Data are given in tabular form, and an index and extensive bibliography are included.

  18. [Nondestructive Evaluation (NDE) Capabilities

    NASA Technical Reports Server (NTRS)

    Born, Martin

    2010-01-01

    These poster boards display the United Space Alliance's (USA) systems and equipment used for Nondestructive Evaluation. These include: (1) the Robotic Inspection Facility, (2) CAT-Scan and Laminography, (3) Laser Surface Profilometry, (4) Remote Eddy Current, (5) Ultrasonic Phased Array, (7) Infrared Flash Thermography, and (8) Backscatter X-Ray (BSX)

  19. Non-Destructive Classification Approaches for Equilibrated Ordinary Chondrites

    NASA Astrophysics Data System (ADS)

    Righter, K.; Harrington, R.; Schroeder, C.; Morris, R. V.

    2013-09-01

    In order to compare a few non-destructive classification techniques with the standard approaches, we have characterized a group of chondrites from the Larkman Nunatak region using magnetic susceptibility and Mössbauer spectroscopy.

  20. A Survey of Librarian Perceptions of Information Literacy Techniques

    ERIC Educational Resources Information Center

    Yearwood, Simone L.; Foasberg, Nancy M.; Rosenberg, Kenneth D.

    2015-01-01

    Teaching research competencies and information literacy is an integral part of the academic librarian's role. There has long been debate among librarians over what are the most effective methods of instruction for college students. Library Faculty members at a large urban university system were surveyed to determine their perceptions of the…

  1. Guidelines for a Training Course in Noise Survey Techniques.

    ERIC Educational Resources Information Center

    Shadley, John; And Others

    The course is designed to train noise survey technicians during a 3-5 day period to make reliable measurements of 75 percent of the noise problems encountered in the community. The more complex noise problems remaining will continue to be handled by experienced specialists. These technicians will be trained to assist State and local governments in…

  2. Sampling for Telephone Surveys: Do the Results Depend on Technique?

    ERIC Educational Resources Information Center

    Franz, Jennifer D.

    Two basic methods exist for drawing probability samples to be used in telephone surveys: directory sampling (from alphabetical or street directories) and random digit dialing (RDD). RDD includes unlisted numbers, whereas directory sampling includes only listed numbers. The goal of this paper is to estimate the effect of failure to include…

  3. The Future of Institutional Surveys: New Concepts, Techniques, and Technologies.

    ERIC Educational Resources Information Center

    Francis, J. Bruce

    1979-01-01

    The survey holds an increasingly important place in institutional advancement. As college and university decision makers turn more and more to their constituencies for support and assistance, a competent information-gathering and processing network becomes crucial. Heuristic v algorithmic designs, Attitude Information System, and the microcomputer…

  4. Guidelines for a Training Course in Noise Survey Techniques.

    ERIC Educational Resources Information Center

    Shadley, John; And Others

    The course is designed to train noise survey technicians during a 3-5 day period to make reliable measurements of 75 percent of the noise problems encountered in the community. The more complex noise problems remaining will continue to be handled by experienced specialists. These technicians will be trained to assist State and local governments in…

  5. Nondestructive Material Testing Using OCT

    NASA Astrophysics Data System (ADS)

    Stifter, D.

    The fact that optical coherence tomography (OCT) provides information on internal structures of scattering tissue in a noninvasive way has led to a broad acceptance of OCT for dedicated biomedical imaging and diagnostics applications. Outside the biomedical field, an irreversible alteration of an object under investigation by the characterization method itself is likewise undesirable, especially in the case that such an object has to be further used with its original state maintained. For this purpose, a variety of so-called nondestructive testing (NDT) methods is nowadays at hand,with OCT as novel technique exhibiting a huge potential to add valuable contributions to nondestructive testing and evaluation of semitransparent, scattering materials with structural features on the micron scale. Therefore, within this chapter, a broad range of applications for OCT in NDT is presented, ranging from examples of industrial quality control over classification and authentication tasks to the evaluation of materials in research and development.The individual applications are listed according to the category of information obtained from the individual measurements, starting with the evaluation of the pure surface structure, proceeding to thickness measurements of layered systems, to imaging of internal 3D structures and finally leading to the determination of functional information.

  6. Educational ultrasound nondestructive testing laboratory.

    PubMed

    Genis, Vladimir; Zagorski, Michael

    2008-09-01

    The ultrasound nondestructive evaluation (NDE) of materials course was developed for applied engineering technology students at Drexel University's Goodwin College of Professional Studies. This three-credit, hands-on laboratory course consists of two parts: the first part with an emphasis on the foundations of NDE, and the second part during which ultrasound NDE techniques are utilized in the evaluation of parts and materials. NDE applications are presented and applied through real-life problems, including calibration and use of the latest ultrasonic testing instrumentation. The students learn engineering and physical principles of measurements of sound velocity in different materials, attenuation coefficients, material thickness, and location and dimensions of discontinuities in various materials, such as holes, cracks, and flaws. The work in the laboratory enhances the fundamentals taught during classroom sessions. This course will ultimately result in improvements in the educational process ["The greater expectations," national panel report, http://www.greaterexpectations.org (last viewed February, 2008); R. M. Felder and R. Brent "The intellectual development of Science and Engineering Students. Part 2: Teaching to promote growth," J. Eng. Educ. 93, 279-291 (2004)] since industry is becoming increasingly reliant on the effective application of NDE technology and the demand on NDE specialists is increasing. NDE curriculum was designed to fulfill levels I and II NDE in theory and training requirements, according to American Society for Nondestructive Testing, OH, Recommended Practice No. SNT-TC-1A (2006).

  7. Nondestructive evaluation of electrodeposited chromium

    NASA Astrophysics Data System (ADS)

    Todaro, Mark E.

    1992-11-01

    Benet Laboratories is pursuing methods for nondestructively evaluating the quality and adhesion of electrodeposited chromium coatings on the bore of large caliber gun tubes. The Army currently has no suitable means for testing such coatings nondestructively. A poor quality or poorly adherent coating shows up only when several test rounds are fired through the tube, removing portions of the coating and exposing the steel underneath. Recent in-house work has investigated both photothermal and ultrasonic methods. The photothermal method involves briefly heating the surface of the chromium with a laser pulse. After the initial heating, the surface temperature decreases as heat diffuses into the coating and substrate. The characteristics of the coating, interface, and substrate affect the surface temperature profile in distinct ways. The temperature of the surface can be measured by observing the emitted infrared radiation with a focused detector or an infrared scanner. Although no experimental data using the photothermal technique has been obtained yet, a one-dimensional finite difference algorithm was used to model temperature changes on the surface of a chromium coating on steel due to an incident energy pulse. The model verifies that with a suitable choice of laser pulse width, one could measure the thermal characteristics of the coating and detect the presence of a thermal discontinuity at the interface.

  8. A survey of GPU-based medical image computing techniques

    PubMed Central

    Shi, Lin; Liu, Wen; Zhang, Heye; Xie, Yongming

    2012-01-01

    Medical imaging currently plays a crucial role throughout the entire clinical applications from medical scientific research to diagnostics and treatment planning. However, medical imaging procedures are often computationally demanding due to the large three-dimensional (3D) medical datasets to process in practical clinical applications. With the rapidly enhancing performances of graphics processors, improved programming support, and excellent price-to-performance ratio, the graphics processing unit (GPU) has emerged as a competitive parallel computing platform for computationally expensive and demanding tasks in a wide range of medical image applications. The major purpose of this survey is to provide a comprehensive reference source for the starters or researchers involved in GPU-based medical image processing. Within this survey, the continuous advancement of GPU computing is reviewed and the existing traditional applications in three areas of medical image processing, namely, segmentation, registration and visualization, are surveyed. The potential advantages and associated challenges of current GPU-based medical imaging are also discussed to inspire future applications in medicine. PMID:23256080

  9. A survey of GPU-based medical image computing techniques.

    PubMed

    Shi, Lin; Liu, Wen; Zhang, Heye; Xie, Yongming; Wang, Defeng

    2012-09-01

    Medical imaging currently plays a crucial role throughout the entire clinical applications from medical scientific research to diagnostics and treatment planning. However, medical imaging procedures are often computationally demanding due to the large three-dimensional (3D) medical datasets to process in practical clinical applications. With the rapidly enhancing performances of graphics processors, improved programming support, and excellent price-to-performance ratio, the graphics processing unit (GPU) has emerged as a competitive parallel computing platform for computationally expensive and demanding tasks in a wide range of medical image applications. The major purpose of this survey is to provide a comprehensive reference source for the starters or researchers involved in GPU-based medical image processing. Within this survey, the continuous advancement of GPU computing is reviewed and the existing traditional applications in three areas of medical image processing, namely, segmentation, registration and visualization, are surveyed. The potential advantages and associated challenges of current GPU-based medical imaging are also discussed to inspire future applications in medicine.

  10. A comparison between finite element modeling and various thermographic non-destructive testing techniques for the quantification of the thermal integrity of macro-brush plasma facing components used in a tokamak

    NASA Astrophysics Data System (ADS)

    Pandya, Santosh P.; Pandya, Shwetang N.; Patil, Yashashri V.; Krishnan, Deepu S.; Murugesan, Menaka; Sharath, D.; Singh, K. Premjit; Khan, Md. Shoaib; Arafat, M.; Biju, N.; Khirwadkar, Samir S.; Govidarajan, Jagannathan; Venkatraman, B.; Balasubramaniam, Krishnan

    2016-02-01

    The plasma facing components (PFCs) inside a tokamak are typically exposed to extremely high heat flux of the order of MW/m2. The brazing quality between the plasma facing materials (PFMs) and the heat sink will determine the structural integrity and hence the effective service life of these PFCs. Suitable non-destructive testing (NDT) techniques for the pre-qualification of these components are thus essential to evaluate their structural integrity at various stages of their service life. Macro-brush type mockups of prototype PFCs with graphite as PFM have been inspected for their brazing quality using different active Infrared (IR)-thermographic NDT techniques. The results obtained from these techniques are compared and discussed. The brazing quality was quantified by establishing a comparison between the experimental results and the results from Finite Element Analysis (FEA). The percentage of contact between the PFM and the substrate was varied in FEA. FEA results when compared with experiments shows that tiles have different amounts of contact with the substrate ranging between 10% and 80%.

  11. Overview of High-Resolution Nondestructive Inspection of the Space Shuttle External Tank (ET) Spray-on-Foam Insulation (SOFI) and Acreage Heat tiles using Focused, Synthetic and Holographical Millimeter Wave Techniques

    NASA Technical Reports Server (NTRS)

    Kharkovsky, S.; Case, J. T.; Zoughi, R.; Hepburn, Frank L.

    2006-01-01

    Space Shuttle Columbia's catastrophic failure has been attributed to a piece of spray-on-foam insulation (SOFI) that was dislodged from the external tank (ET) and struck the leading edge of the left wing. A piece of SOFI was also dislodged in the recent Space Shuttle Discovery's flight. From immediately after the Columbia accident, microwave and millimeter wave nondestructive testing methods were considered as potential effective inspection tools for evaluating the integrity of the SOFI. To this end and as a result of these efforts, both real-focused, synthetic focusing and holographical techniques, at a wide range of frequencies covering 24 GHz to 150 GHz, have been developed for this purpose. Images of various complex SOFI panels with a wide range of embedded anomalies (representing real potential defects) have been produced using these techniques, including relatively small anomalies located near complex structural features representative of the external tank. These real-focused and 3D holographical images have effectively demonstrated the utility of these methods for SOFI inspection as being viable, robust, repeatable, simple, portable and relatively inexpensive (tens of $K as opposed to hundreds of $K). In addition, the potential viability of these methods for inspecting acreage heat tiles have has been demonstrated. This paper presents an overview of these activities, representative images of these panels using all of the imaging techniques used and a discussion of the practical attributes of these inspection methods.

  12. Overview of High-Resolution Nondestructive Inspection of the Space Shuttle External Tank (ET) Spray-on-Foam Insulation (SOFI) and Acreage Heat tiles using Focused, Synthetic and Holographical Millimeter Wave Techniques

    NASA Technical Reports Server (NTRS)

    Kharkovsky, S.; Case, J. T.; Zoughi, R.; Hepburn, Frank L.

    2006-01-01

    Space Shuttle Columbia's catastrophic failure has been attributed to a piece of spray-on-foam insulation (SOFI) that was dislodged from the external tank (ET) and struck the leading edge of the left wing. A piece of SOFI was also dislodged in the recent Space Shuttle Discovery's flight. From immediately after the Columbia accident, microwave and millimeter wave nondestructive testing methods were considered as potential effective inspection tools for evaluating the integrity of the SOFI. To this end and as a result of these efforts, both real-focused, synthetic focusing and holographical techniques, at a wide range of frequencies covering 24 GHz to 150 GHz, have been developed for this purpose. Images of various complex SOFI panels with a wide range of embedded anomalies (representing real potential defects) have been produced using these techniques, including relatively small anomalies located near complex structural features representative of the external tank. These real-focused and 3D holographical images have effectively demonstrated the utility of these methods for SOFI inspection as being viable, robust, repeatable, simple, portable and relatively inexpensive (tens of $K as opposed to hundreds of $K). In addition, the potential viability of these methods for inspecting acreage heat tiles have has been demonstrated. This paper presents an overview of these activities, representative images of these panels using all of the imaging techniques used and a discussion of the practical attributes of these inspection methods.

  13. A comparison between finite element modeling and various thermographic non-destructive testing techniques for the quantification of the thermal integrity of macro-brush plasma facing components used in a tokamak.

    PubMed

    Pandya, Santosh P; Pandya, Shwetang N; Patil, Yashashri V; Krishnan, Deepu S; Murugesan, Menaka; Sharath, D; Singh, K Premjit; Khan, Md Shoaib; Arafat, M; Biju, N; Khirwadkar, Samir S; Govidarajan, Jagannathan; Venkatraman, B; Balasubramaniam, Krishnan

    2016-02-01

    The plasma facing components (PFCs) inside a tokamak are typically exposed to extremely high heat flux of the order of MW/m(2). The brazing quality between the plasma facing materials (PFMs) and the heat sink will determine the structural integrity and hence the effective service life of these PFCs. Suitable non-destructive testing (NDT) techniques for the pre-qualification of these components are thus essential to evaluate their structural integrity at various stages of their service life. Macro-brush type mockups of prototype PFCs with graphite as PFM have been inspected for their brazing quality using different active Infrared (IR)-thermographic NDT techniques. The results obtained from these techniques are compared and discussed. The brazing quality was quantified by establishing a comparison between the experimental results and the results from Finite Element Analysis (FEA). The percentage of contact between the PFM and the substrate was varied in FEA. FEA results when compared with experiments shows that tiles have different amounts of contact with the substrate ranging between 10% and 80%.

  14. Nondestructive inspection perspectives

    NASA Technical Reports Server (NTRS)

    Froom, Douglas A.

    1992-01-01

    This paper presents ideas for consideration by those concerned with commercial aircraft nondestructive inspection (NDI). The perspective is that of an individual with a background in military aircraft NDI, and important differences are indicated between the commercial NDI and military NDI activities. In particular, it is significantly more expensive to implement some new NDI technology, and therefore, in-depth cost-benifit studies for commercial users are recommended.

  15. Concept of nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Chern, E. J.

    1991-01-01

    The history of nondestructive evaluation, a recently evolved basic testing philosophy, and some application of NDE are examined with emphasis on aerospace applications. The discussion covers the definition of NDE, chronological development, NDE methods and systems, the use of NDE for process control, NDE for ceramics and composites, NDE for fracture control in glass, and science aspects of NDE. Specific examples of NDE applications are given.

  16. Emerging nondestructive inspection methods for aging aircraft

    SciTech Connect

    Beattie, A; Dahlke, L; Gieske, J

    1994-01-01

    This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with a discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.

  17. Hybrid holographic non-destructive test system

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1978-01-01

    An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.

  18. USES OF MARKETING TECHNIQUES THE U. S. GEOLOGICAL SURVEY.

    USGS Publications Warehouse

    McDermott, Michael P.

    1983-01-01

    The use of marketing techniques by government agencies to provide more efficient and effective dissemination of their information is a fairly recent development. A recessive economy, and increased scrutiny of operations have become a powerful incentive to maximize revenues and minimize expenses wherever possible as long as the primary mission of public service is satisfactorily met.

  19. Survey of Temperature Measurement Techniques For Studying Underwater Shock Waves

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Alderfer, David W.

    2004-01-01

    Several optical methods for measuring temperature near underwater shock waves are reviewed and compared. The relative merits of the different techniques are compared, considering accuracy, precision, ease of use, applicable temperature range, maturity, spatial resolution, and whether or not special additives are required.

  20. Kalman Filter Techniques for Control of Repeated Economic Surveys.

    DTIC Science & Technology

    1980-09-30

    example, Bellman (1970). We may now write our cost function J for the two-item repeated survey problem with scalar sample size nd and sampling...deterministic quantities. - 13- Solving (16) for C we obtain, strictly paralleling (14), C = -(T/2) Q + QI/2 [T Efl /N(k)] Q-l/2 R Q-i/2 + (T2/4)11/ 2 QI/2 so...instantaneously processed) at tk As shown in Jawinski (1970), if we integrate the process equation in (19) over intervals [t,tk+l , we may write tk+1 X(tk+l) = X

  1. Nondestructive Profilometry of Optical Nanofibers.

    PubMed

    Madsen, Lars S; Baker, Christopher; Rubinsztein-Dunlop, Halina; Bowen, Warwick P

    2016-12-14

    Single-mode optical nanofibers are a central component of a broad range of applications and emerging technologies. Their fabrication has been extensively studied over the past decade, but imaging of the final submicrometer products has been restricted to destructive or low-precision techniques. Here, we demonstrate an optical scattering-based scanning method that uses a probe nanofiber to locally scatter the evanescent field of a sample nanofibre. The method does not damage the sample nanofiber and is easily implemented by only using the same equipment as in a standard fiber-puller setup. We demonstrate the subnanometer radial resolution at video rates (0.7 nm in 10 ms) on single mode nanofibers, allowing for a complete high-precision profile to be obtained within minutes of fabrication. The method thus enables nondestructive, fast, and precise characterization of optical nanofibers, with applications ranging from optical sensors and cold atom traps to nonlinear optics.

  2. A Survey of Terrain Modeling Technologies and Techniques

    DTIC Science & Technology

    2007-09-01

    the Government with the abil- ity to contract for LIDAR data collection while ensuring accuracy and con- sistency of DTMs and geospatial models derived...techniques and methods for processing LIDAR and color imagery data to construct a high-fidelity DTM , 3-D geospatial model, and attributed geospatial...team also delivered a LIDAR intensity image of the terrain with same resolution as DTM and vegetation models in two forms: pixel level and geometrical

  3. A Survey and Synthesis of Solar Cycle Prediction Techniques

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Wilson, Robert M.; Reichmann, Edwin J.

    1999-01-01

    A number of techniques for predicting solar activity on a solar cycle time scale are identified, described, and tested with historical data. Some techniques, e.g. regression and curve-fitting, work well as solar activity approaches maximum and provide a complete description of future activity, while others, e.g. geomagnetic precursors, work well near solar minimum but only provide an estimate of the amplitude of the cycle. A synthesis of different techniques is shown to provide a more accurate and useful forecast of solar cycle activity levels. A combination of two uncorrelated geomagnetic precursor techniques provides the most accurate prediction for the amplitude of a solar activity cycle at a time well before activity minimum. This Combined Precursor Method gives a smoothed sunspot number maximum of 154+/-21 at the 95% level of confidence for the next cycle maximum. A mathematical function dependent upon the time of cycle initiation and the cycle amplitude then describes the level of solar activity for the next complete cycle. As the time of cycle maximum approaches a better estimate of the cycle activity is obtained by including the fit between previous activity levels and this function. This Combined Solar Cycle Activity Forecast gives, as of January 1999, a smoothed sunspot maximum of 146+/-20 at the 95% level of confidence for the next cycle maximum. The success of the geomagnetic precursors in predicting future solar activity suggests that solar magnetic phenomena at latitudes above the sunspot activity belts are linked to solar activity which occurs many years later in the lower latitudes.

  4. A Survey of Computational Intelligence Techniques in Protein Function Prediction

    PubMed Central

    Tiwari, Arvind Kumar; Srivastava, Rajeev

    2014-01-01

    During the past, there was a massive growth of knowledge of unknown proteins with the advancement of high throughput microarray technologies. Protein function prediction is the most challenging problem in bioinformatics. In the past, the homology based approaches were used to predict the protein function, but they failed when a new protein was different from the previous one. Therefore, to alleviate the problems associated with homology based traditional approaches, numerous computational intelligence techniques have been proposed in the recent past. This paper presents a state-of-the-art comprehensive review of various computational intelligence techniques for protein function predictions using sequence, structure, protein-protein interaction network, and gene expression data used in wide areas of applications such as prediction of DNA and RNA binding sites, subcellular localization, enzyme functions, signal peptides, catalytic residues, nuclear/G-protein coupled receptors, membrane proteins, and pathway analysis from gene expression datasets. This paper also summarizes the result obtained by many researchers to solve these problems by using computational intelligence techniques with appropriate datasets to improve the prediction performance. The summary shows that ensemble classifiers and integration of multiple heterogeneous data are useful for protein function prediction. PMID:25574395

  5. A survey of computational intelligence techniques in protein function prediction.

    PubMed

    Tiwari, Arvind Kumar; Srivastava, Rajeev

    2014-01-01

    During the past, there was a massive growth of knowledge of unknown proteins with the advancement of high throughput microarray technologies. Protein function prediction is the most challenging problem in bioinformatics. In the past, the homology based approaches were used to predict the protein function, but they failed when a new protein was different from the previous one. Therefore, to alleviate the problems associated with homology based traditional approaches, numerous computational intelligence techniques have been proposed in the recent past. This paper presents a state-of-the-art comprehensive review of various computational intelligence techniques for protein function predictions using sequence, structure, protein-protein interaction network, and gene expression data used in wide areas of applications such as prediction of DNA and RNA binding sites, subcellular localization, enzyme functions, signal peptides, catalytic residues, nuclear/G-protein coupled receptors, membrane proteins, and pathway analysis from gene expression datasets. This paper also summarizes the result obtained by many researchers to solve these problems by using computational intelligence techniques with appropriate datasets to improve the prediction performance. The summary shows that ensemble classifiers and integration of multiple heterogeneous data are useful for protein function prediction.

  6. A survey of reflectometry techniques with applications to TFTR

    SciTech Connect

    Collazo, I.; Stacey, W.M.; Wilgen, J.; Hanson, G.; Bigelow, T.; Thomas, C.E.; Bretz, N.

    1993-12-01

    This report presents a review of reflectometry with particular attention to eXtraordinary mode (X-mode) reflectometry using the novel technique of dual frequency differential phase. The advantage of using an X-mode wave is that it can probe the edge of the plasma with much higher resolution and using a much smaller frequency range than with the Ordinary mode (O-Mode). The general problem with previous full phase reflectometry techniques is that of keeping track of the phase (on the order of 1000 fringes) as the frequency is swept over the band. The dual frequency phase difference technique has the advantage that since it is keeping track of the phase difference of two frequencies with a constant frequency separation, the fringe counting is on the order of only 3 to 5 fringes. This fringe count, combined with the high resolution of the X-mode wave and the small plasma access requirements of reflectometry, make X-mode reflectometry a very attractive diagnostic for today`s experiments and future fusion devices.

  7. GPR as a Low Impact Paleontogical Survey Technique

    NASA Astrophysics Data System (ADS)

    Sturdevant, G. C.; Leverence, R.; Stewart, R.

    2013-12-01

    The Deweyville Formation, a Pleistocene fluvial sandstone, is a prolific source of megafaunal fossils from periods of low stand environmental conditions. GPR was employed in an environmentally sensitive area in close proximity to a salt dome in Northwest Harris County, Texas as a method of evaluating the probable paleo-depositional environment and to prospect for potential further site development of two distinct fossiliferous zones. The primary zone of interest is a lag gravel bounded sand responsible for producing a regionally unique fossil assemblage including South American megafauna (Lundelius et al, 2013). The secondary zone of interest contains undisturbed mammoth remains housed in coarse white sand emplaced on top of a clay drape which has been hypothesized to represent an oxbow lake formed by the meandering paleo-Brazos river. With an accurate map of the paleo-channel planning future activity can focus on maximizing fossil recovery and minimizing site impact. Pulse EKKO 250 MHz, 400MHz, and 1GHz system was employed in a prospect area proximal to the secondary site to calibrate and evaluate these systems for their resolution and penetration depth in the modern sediments. The data was processed using EKKO Mapper and EKKO View Deluxe software packages, 3d volumes were produced and sliced. Preliminary results from the 250 MHz demonstrate successful imaging of the sand-clay interface. After these surveys were run a small portion of the site was excavated to confirm the estimated velocities, the observed anomalies, and refine our modeling and interpretation, and improve grid design for further surveys. It was confirmed that the sand-clay interface was easily observable using GPR, however the grid spacing proved to be too wide, leading to artifacts in the 3d volume produced.

  8. Nondestructive testing methods for 55-gallon, waste storage drums

    SciTech Connect

    Ferris, R.H.; Hildebrand, B.P.; Hockey, R.L.; Riechers, D.M.; Spanner, J.C.; Duncan, D.R.

    1993-06-01

    The Westinghouse Hanford Company (WHC) authorized Pacific Northwest Laboratory (PNL) to conduct a feasibility study to identify promising nondestructive testing (NDT) methods for detecting general and localized (both pitting and pinhole) corrosion in the 55-gal drums that are used to store solid waste materials at the Hanford Site. This document presents results obtained during a literature survey, identifies the relevant reference materials that were reviewed, provides a technical description of the methods that were evaluated, describes the laboratory tests that were conducted and their results, identifies the most promising candidate methods along with the rationale for these selections, and includes a work plan for recommended follow-on activities. This report contains a brief overview and technical description for each of the following NDT methods: magnetic testing techniques; eddy current testing; shearography; ultrasonic testing; radiographic computed tomography; thermography; and leak testing with acoustic detection.

  9. Data indexing techniques for the EUVE all-sky survey

    NASA Technical Reports Server (NTRS)

    Lewis, J.; Saba, V.; Dobson, C.

    1992-01-01

    This poster describes techniques developed for manipulating large full-sky data sets for the Extreme Ultraviolet Explorer project. The authors have adapted the quatrilateralized cubic sphere indexing algorithm to allow us to efficiently store and process several types of large data sets, such as full-sky maps of photon counts, exposure time, and count rates. A variation of this scheme is used to index sparser data such as individual photon events and viewing times for selected areas of the sky, which are eventually used to create EUVE source catalogs.

  10. A survey of various enhancement techniques for square rings antennas

    NASA Astrophysics Data System (ADS)

    Mumin, Abdul Rashid O.; Alias, Rozlan; Abdullah, Jiwa; Abdulhasan, Raed Abdulkareem; Ali, Jawad; Dahlan, Samsul Haimi; Awaleh, Abdisamad A.

    2017-09-01

    The square ring shape becomes a famous reconfiguration on antenna design. The researchers have been developed the square ring by different configurations. It has high efficiency and simple calculation method. The performance enhancement for an antenna is the main reason to use this setting. Furthermore, the multi-objectives for the antenna also are considered. In this paper, different studies of square ring shape are discussed. This shape is developed in five different techniques, which are the gain enhancement, dual band antenna, reconfigurable antenna, CSRR, and circularly polarization. Moreover, the validation between these configurations also demonstrates for square ring shapes. In particular, the square ring slot improved the gain by 4.3 dB, provide dual band resonance at 1.4 and 2.6 GHz while circular polarization at 1.54 GHz, and multi-mode antenna. However, square ring strip achieved an excellent band rejection on UWB antenna at 5.5 GHz. The square ring slot length is the most influential factor on the antenna performance, which refers to the free space wavelength. Finally, comparisons between these techniques are presented.

  11. Use of GPR technique in surveying gravel road wearing course

    NASA Astrophysics Data System (ADS)

    Saarenketo, Timo; Vesa, Heikki

    2000-04-01

    During summer 1998 a series of tests were conducted in Finland in order to find out how Ground Penetrating Radar (GPR) technology can be utilized at both the project and network level, when surveying the wearing course thickness of gravel roads. The second objective was to investigate the possibilities of applying dielectricity information obtained using the GPR surface reflection method when determining the quality of the gravel road wearing course. In this study GPR was tested at the project level on highway 9241 Simo in Northern Finland, where the information provided by the GPR and laboratory research was used in designing and proportioning a new wearing course. In the network level studies, performed in the maintenance areas of Kemi and Karstula in Northern and Central Finland the goal for using GPR was to inspect the condition and thickness of the wearing course and evaluate the need for additional wearing course material. The total length of the roads under survey was approximately 200 km and both a 1.5 GHz ground-coupled antenna and a 1.0 GHz horn antenna were tested in this study. The research results show that GPR can be used to measure the thickness of the wearing course, the average measuring error against reference drilling measurements being 25 mm, which is considerably larger than the error of radar measurements in paved roads. To a great extent this is due to the fact that the thickness of the wearing course varies greatly even in the road's cross-section and thus a single reference thickness does not represent the actual thickness of the area measured with the GPR. The wearing course can often get mixed up with lower layers, which makes it difficult to determine the exact layer interfaces. For this reason reference information must always be used along with the GPR measurement results. Of the two GPR antennae tested, the horn antenna proved to be the more effective in measurements. The dielectric value of the wearing course, measured using the horn

  12. Nondestructive tests of regenerative chambers. [evaluating nondestructive methods of determining metal bond integrity

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Vecchies, L.; Wood, R.

    1974-01-01

    The capabilities and limitations of nondestructive evaluation methods were studied to detect and locate bond deficiencies in regeneratively cooled thrust chambers for rocket engines. Flat test panels and a cylinder were produced to simulate regeneratively cooled thrust chamber walls. Planned defects with various bond integrities were produced in the panels to evaluate the sensitivity, accuracy, and limitations of nondestructive methods to define and locate bond anomalies. Holography, acoustic emission, and ultrasonic scan were found to yield sufficient data to discern bond quality when used in combination and in selected sequences. Bonding techniques included electroforming and brazing. Materials of construction included electroformed nickel bonded to Nickel 200 and OFHC copper, electroformed copper bonded to OFHC copper, and 300 series stainless steel brazed to OFHC copper. Variations in outer wall strength, wall thickness, and defect size were evaluated for nondestructive test response.

  13. Nondestructive evaluation of creep damage and life prediction of Ni-base superalloy used in advanced gas turbine blades by electrochemical technique

    NASA Astrophysics Data System (ADS)

    Komazaki, Shin-ichi; Shoji, Tetsuo; Abe, Iwao; Okada, Ikuo

    1999-12-01

    In order to develop a creep life assessment technique for directionally solidified Ni-base superalloy CM247LC, changes in electrochemical properties due to creep have been investigated. Experimental results on electrochemical polarization measurements revealed that the peak current density "Ip" and "Ipr" which appeared at a specific potential during potentiodynamic polarization reactivation measurements in dilute glyceregia solution linearly increased with a life fraction in early stage of the creep life and were uniquely correlated with Arrhenius type parameter "(t/tr)exp(-Qc/RT)." As a consequence, the creep life fraction can be estimated with high accuracy by the electrochemical technique.

  14. Survey of Natural Language Processing Techniques in Bioinformatics

    PubMed Central

    Zeng, Zhiqiang; Shi, Hua; Wu, Yun; Hong, Zhiling

    2015-01-01

    Informatics methods, such as text mining and natural language processing, are always involved in bioinformatics research. In this study, we discuss text mining and natural language processing methods in bioinformatics from two perspectives. First, we aim to search for knowledge on biology, retrieve references using text mining methods, and reconstruct databases. For example, protein-protein interactions and gene-disease relationship can be mined from PubMed. Then, we analyze the applications of text mining and natural language processing techniques in bioinformatics, including predicting protein structure and function, detecting noncoding RNA. Finally, numerous methods and applications, as well as their contributions to bioinformatics, are discussed for future use by text mining and natural language processing researchers. PMID:26525745

  15. Some fuzzy techniques for staff selection process: A survey

    NASA Astrophysics Data System (ADS)

    Md Saad, R.; Ahmad, M. Z.; Abu, M. S.; Jusoh, M. S.

    2013-04-01

    With high level of business competition, it is vital to have flexible staff that are able to adapt themselves with work circumstances. However, staff selection process is not an easy task to be solved, even when it is tackled in a simplified version containing only a single criterion and a homogeneous skill. When multiple criteria and various skills are involved, the problem becomes much more complicated. In adddition, there are some information that could not be measured precisely. This is patently obvious when dealing with opinions, thoughts, feelings, believes, etc. One possible tool to handle this issue is by using fuzzy set theory. Therefore, the objective of this paper is to review the existing fuzzy techniques for solving staff selection process. It classifies several existing research methods and identifies areas where there is a gap and need further research. Finally, this paper concludes by suggesting new ideas for future research based on the gaps identified.

  16. Survey of Natural Language Processing Techniques in Bioinformatics.

    PubMed

    Zeng, Zhiqiang; Shi, Hua; Wu, Yun; Hong, Zhiling

    2015-01-01

    Informatics methods, such as text mining and natural language processing, are always involved in bioinformatics research. In this study, we discuss text mining and natural language processing methods in bioinformatics from two perspectives. First, we aim to search for knowledge on biology, retrieve references using text mining methods, and reconstruct databases. For example, protein-protein interactions and gene-disease relationship can be mined from PubMed. Then, we analyze the applications of text mining and natural language processing techniques in bioinformatics, including predicting protein structure and function, detecting noncoding RNA. Finally, numerous methods and applications, as well as their contributions to bioinformatics, are discussed for future use by text mining and natural language processing researchers.

  17. Overview of the latest nondestructive assay technology

    SciTech Connect

    Geist, William H; Santi, Peter A; Swinhoe, Martyn T

    2009-01-01

    Nondestructive Assay (NDA) techniques are an important tool for the safeguarding of nuclear materials. NDA techniques are used by inspectors from both domestic agencies and international agencies such as the International Atomic Energy Agency as well as site level nuclear material management programs to verify that inventories of nuclear materials. This technology has been in development for over 40 years and significant improvements in detector capabilities, electronics processing and data analysis has lead to new detection capabilities and greatly improved quantification of nuclear materials. Many of the improvements over the last decade have resulted from improved computing power. This has lead to the ability to collect and analyze data in ways not possible only years ago. This poster will present some of the improvements of nondestructive assay technologies over the past several years and the implementation of these technologies in nuclear safeguards programs.

  18. Nondestructive material characterization

    DOEpatents

    Deason, Vance A.; Johnson, John A.; Telschow, Kenneth L.

    1991-01-01

    A method and apparatus for nondestructive material characterization, such as identification of material flaws or defects, material thickness or uniformity and material properties such as acoustic velocity. The apparatus comprises a pulsed laser used to excite a piezoelectric (PZ) transducer, which sends acoustic waves through an acoustic coupling medium to the test material. The acoustic wave is absorbed and thereafter reflected by the test material, whereupon it impinges on the PZ transducer. The PZ transducer converts the acoustic wave to electrical impulses, which are conveyed to a monitor.

  19. Nondestructive equipment study

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Identification of existing nondestructive Evaluation (NDE) methods that could be used in a low Earth orbit environment; evaluation of each method with respect to the set of criteria called out in the statement of work; selection of the most promising NDE methods for further evaluation; use of selected NDE methods to test samples of pressure vessel materials in a vacuum; pressure testing of a complex monolythic pressure vessel with known flaws using acoustic emissions in a vacuum; and recommendations for further studies based on analysis and testing are covered.

  20. Nondestructive Testing Information Analysis Center, 1979.

    DTIC Science & Technology

    1980-09-01

    2 Table I Major Current Methods of Nondestructive Testing * RADIdCRAPHIC AND RADIOMETRIC TESTING X- rays Gamma rays Neutrons Filmless techniques...OPTICAL TESTING Visual testing Optical reflectometry and transmission Holography * THERMAL TESTING Infrared radiometry The rmography 13 The present...Date 0416 The Boeing Wichita Co. Bibliography $ 90 2/27/79 0417 FDA-WEAC Service Info. n/c 2/28/79 0418 Gull Airborne Instruments Tech. Inq. n/c 3/7

  1. A Review of Non-destructive Detection for Fruit Quality

    NASA Astrophysics Data System (ADS)

    Gao, Haisheng; Zhu, Fengmei; Cai, Jinxing

    An overview of non-destructive detection in quality of post-harvest fruit was presented in this paper, and the research and application were discussed. This paper elaborated the fruit quality detection methods which were based on one of the following properties: optical properties, sonic vibration, machine vision technique, nuclear magnetic resonance (NMR), electronic noses, electrical properties, computed tomography. At last, the main problems of non-destructive detection in application were also explained.

  2. Complete denture impression techniques practiced by private dental practitioners: a survey.

    PubMed

    Kakatkar, Vinay R

    2013-09-01

    Impression making is an important step in fabricating complete dentures. A survey to know the materials used and techniques practiced while recording complete denture impressions was conducted. It is disheartening to know that 33 % practitioners still use base plate custom trays to record final impressions. 8 % still use alginate for making final impressions. An acceptable technique for recording CD impressions is suggested.

  3. A survey of techniques for refrigeration, reliquefaction, and production of slush for hydrogen

    NASA Technical Reports Server (NTRS)

    Overcash, Dan R.

    1990-01-01

    Several techniques were surveyed for the refrigeration, reliquefaction and production of slush from hydrogen. The techniques included auger; bubbling helium gas; Simon desorption; the Petlier effect; Joule-Kelvin expansion using Stirling, Brayton, and Viulleumirer approaches; rotary reciprocating; a dilution refrigerator; adiabatic demagnetization of a paramagnetic salt; and adiabatic magnetization of a superconductor.

  4. Manufacturing Methods and Technology (MANTECH) Program. Quality Control and Nondestructive Evaluation Techniques for Composites. Part VI. Acoustic Emission - A State-of-the-Art Review.

    DTIC Science & Technology

    1983-05-01

    characterization and testing of composite materials and struc- tures has been written. First, an extensive bibliography of over 300 references of the...024739-3 (3-volume set)]. 1-10 1~ I I ** 14. P. Bee, A. Chaari, P. Gaillard, and J. F. Qhretien. "Pattern Recognition Technique for Characterization ...Gardner. "The Characterization of Dawage Growth in Advanced Composites byIAcoustic Emission tonitoring." pp 180-181 in Paper Summaries: ASNT 36th

  5. Non-destructive optical clearing technique enhances optical coherence tomography (OCT) for real-time, 3D histomorphometry of brain tissue (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Paul, Akshay; Chang, Theodore H.; Chou, Li-Dek; Ramalingam, Tirunelveli S.

    2016-03-01

    Evaluation of neurodegenerative disease often requires examination of brain morphology. Volumetric analysis of brain regions and structures can be used to track developmental changes, progression of disease, and the presence of transgenic phenotypes. Current standards for microscopic investigation of brain morphology are limited to detection of superficial structures at a maximum depth of 300μm. While histological techniques can provide detailed cross-sections of brain structures, they require complicated tissue preparation and the ultimate destruction of the sample. A non-invasive, label-free imaging modality known as Optical Coherence Tomography (OCT) can produce 3-dimensional reconstructions through high-speed, cross-sectional scans of biological tissue. Although OCT allows for the preservation of intact samples, the highly scattering and absorbing properties of biological tissue limit imaging depth to 1-2mm. Optical clearing agents have been utilized to increase imaging depth by index matching and lipid digestion, however, these contemporary techniques are expensive and harsh on tissues, often irreversibly denaturing proteins. Here we present an ideal optical clearing agent that offers ease-of-use and reversibility. Similar to how SeeDB has been effective for microscopy, our fructose-based, reversible optical clearing technique provides improved OCT imaging and functional immunohistochemical mapping of disease. Fructose is a natural, non-toxic sugar with excellent water solubility, capable of increasing tissue transparency and reducing light scattering. We will demonstrate the improved depth-resolving performance of OCT for enhanced whole-brain imaging of normal and diseased murine brains following a fructose clearing treatment. This technique potentially enables rapid, 3-dimensional evaluation of biological tissues at axial and lateral resolutions comparable to histopathology.

  6. A Survey of Techniques for Modeling and Improving Reliability of Computing Systems

    SciTech Connect

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-04-24

    Recent trends of aggressive technology scaling have greatly exacerbated the occurrences and impact of faults in computing systems. This has made `reliability' a first-order design constraint. To address the challenges of reliability, several techniques have been proposed. In this study, we provide a survey of architectural techniques for improving resilience of computing systems. We especially focus on techniques proposed for microarchitectural components, such as processor registers, functional units, cache and main memory etc. In addition, we discuss techniques proposed for non-volatile memory, GPUs and 3D-stacked processors. To underscore the similarities and differences of the techniques, we classify them based on their key characteristics. We also review the metrics proposed to quantify vulnerability of processor structures. Finally, we believe that this survey will help researchers, system-architects and processor designers in gaining insights into the techniques for improving reliability of computing systems.

  7. A Survey of Techniques for Modeling and Improving Reliability of Computing Systems

    DOE PAGES

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-04-24

    Recent trends of aggressive technology scaling have greatly exacerbated the occurrences and impact of faults in computing systems. This has made `reliability' a first-order design constraint. To address the challenges of reliability, several techniques have been proposed. In this study, we provide a survey of architectural techniques for improving resilience of computing systems. We especially focus on techniques proposed for microarchitectural components, such as processor registers, functional units, cache and main memory etc. In addition, we discuss techniques proposed for non-volatile memory, GPUs and 3D-stacked processors. To underscore the similarities and differences of the techniques, we classify them based onmore » their key characteristics. We also review the metrics proposed to quantify vulnerability of processor structures. Finally, we believe that this survey will help researchers, system-architects and processor designers in gaining insights into the techniques for improving reliability of computing systems.« less

  8. A rapid survey technique for Tropilaelaps mite (Mesostigmata: Laelapidae) detection.

    PubMed

    Pettis, Jeffery S; Rose, Robyn; Lichtenberg, Elinor M; Chantawannakul, Panuwan; Buawangpong, Ninat; Somana, Weeraya; Sukumalanand, Prachaval; Vanengelsdorp, Dennis

    2013-08-01

    Parasitic Tropilaelaps (Delfinado and Baker) mites are a damaging pest of European honey bees (Apis mellifera L.) in Asia. These mites represent a significant threat if introduced to other regions of the world, warranting implementation of Tropilaelaps mite surveillance in uninfested regions. Current Tropilaelaps mite-detection methods are unsuitable for efficient large scale screening. We developed and tested a new bump technique that consists of firmly rapping a honey bee brood frame over a collecting pan. Our method was easier to implement than current detection tests, reduced time spent in each apiary, and minimized brood destruction. This feasibility increase overcomes the test's decreased rate of detecting infested colonies (sensitivity; 36.3% for the bump test, 54.2% and 56.7% for the two most sensitive methods currently used in Asia). Considering this sensitivity, we suggest that screening programs sample seven colonies per apiary (independent of apiary size) and 312 randomly selected apiaries in a region to be 95% sure of detecting an incipient Tropilaelaps mite invasion. Further analyses counter the currently held view that Tropilaelaps mites prefer drone bee brood cells. Tropilaelaps mite infestation rate was 3.5 +/- 0.9% in drone brood and 5.7 +/- 0.6% in worker brood. We propose the bump test as a standard tool for monitoring of Tropilaelaps mite presence in regions thought to be free from infestation. However, regulators may favor the sensitivity of the Drop test (collecting mites that fall to the bottom of a hive on sticky boards) over the less time-intensive Bump test.

  9. A nondestructive method for continuously monitoring plant growth

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, S. H.

    1985-01-01

    In the past, plant growth generally has been measured using destructive methods. This paper describes a nondestructive technique for continuously monitoring plant growth. The technique provides a means of directly and accurately measuring plant growth over both short and long time intervals. Application of this technique to the direct measurement of plant growth rates is illustrated using corn (Zea mays L.) as an example.

  10. Quantifying Stream Habitat: Relative Effort Versus Quality of Competing Remote Sensing & Ground-Based Survey Techniques

    NASA Astrophysics Data System (ADS)

    Bangen, S. G.; Wheaton, J. M.; Bouwes, N.

    2010-12-01

    Numerous field and analytical methods exist to assist in the quantification of the quantity and quality of in-stream habitat for salmonids. These methods range from field sketches or ‘tape and stick’ ground-based surveys, through to spatially explicit topographic and aerial photographic surveys from a mix of ground-based and remotely sensed airborne platforms. Although some investigators have assessed the quality of specific individual survey methods, the inter-comparison of competing techniques across a diverse range of habitat conditions (wadeable headwater channels to non-wadeable mainstem channels) has not yet been elucidated. In this study, we seek to quantify relative quality (i.e. accuracy, precision, extent) of habitat metrics and inventories derived from different ground-based and remotely sensed surveys of varying degrees of sophistication, as well as enumerate the effort and cost in completing the surveys. Over the summer of 2010, seven sample reaches of varying habitat complexity were surveyed in the Lemhi River Basin, Idaho, USA. Three different traditional (“stick and tape”) survey techniques were used, including a variant using map-grade GPS. Complete topographic/bathymetric surveys were attempted at each site using separate rtkGPS, total station, ground-based LiDaR, boat-based echo-sounding (w/ ADCP), traditional airborne LiDaR, and imagery-based spectral methods. Separate, georectified aerial imagery surveys were acquired using a tethered blimp, a drone UAV, and a traditional fixed-wing aircraft. Preliminary results from the surveys highlight that no single technique works across the full range of conditions where stream habitat surveys are needed. The results are helpful for understanding the strengths and weaknesses of each approach in specific conditions, and how a hybrid of data acquisition methods can be used to build a more complete quantification of habitat conditions in rivers.

  11. Tracking Color Shift in Ballpoint Pen Ink Using Photoshop Assisted Spectroscopy: A Nondestructive Technique Developed to Rehouse a Nobel Laureate's Manuscript.

    PubMed

    Wright, Kristi; Herro, Holly

    2016-01-01

    Many historically and culturally significant documents from the mid-to-late twentieth century were written in ballpoint pen inks, which contain light-sensitive dyes that present problems for collection custodians and paper conservators. The conservation staff at the National Library of Medicine (NLM), National Institutes of Health, conducted a multiphase project on the chemistry and aging of ballpoint pen ink that culminated in the development of a new method to detect aging of ballpoint pen ink while examining a variety of storage environments. NLM staff determined that ballpoint pen ink color shift can be detected noninvasively using image editing software. Instructions are provided on how to detect color shift in digitized materials using a technique developed specifically for this project-Photoshop Assisted Spectroscopy.(1) The study results offer collection custodians storage options for historic documents containing ballpoint pen ink.

  12. Nondestructive evaluation (NDE) of composite-to-metal bond interface of a wind turbine blade using an acousto-ultrasonic technique

    SciTech Connect

    Gieske, J.H.; Rumsey, M.A.

    1996-12-31

    An acousto-ultrasonic inspection technique was developed to evaluate the structural integrity of the epoxy bond interface between a metal insert and the fiber glass epoxy composite of a wind turbine blade. Data was generated manually as well as with a PC based data acquisition and display system. C-scan imaging using a portable ultrasonic scanning system provided an area mapping of the delamination or disbond due to fatigue testing and normal field operation conditions of the turbine blade. Comparison of the inspection data with a destructive visual examination of the bond interface to determine the extent of the disbond showed good agreement between the acousto-ultrasonic inspection data and the visual data.

  13. Bio-functions and molecular carbohydrate structure association study in forage with different source origins revealed using non-destructive vibrational molecular spectroscopy techniques.

    PubMed

    Ji, Cuiying; Zhang, Xuewei; Yan, Xiaogang; Mostafizar Rahman, M; Prates, Luciana L; Yu, Peiqiang

    2017-08-05

    The objectives of this study were to: 1) investigate forage carbohydrate molecular structure profiles; 2) bio-functions in terms of CHO rumen degradation characteristics and hourly effective degradation ratio of N to OM (HEDN/OM), and 3) quantify interactive association between molecular structures, bio-functions and nutrient availability. The vibrational molecular spectroscopy was applied to investigate the structure feature on a molecular basis. Two sourced-origin alfalfa forages were used as modeled forages. The results showed that the carbohydrate molecular structure profiles were highly linked to the bio-functions in terms of rumen degradation characteristics and hourly effective degradation ratio. The molecular spectroscopic technique can be used to detect forage carbohydrate structure features on a molecular basis and can be used to study interactive association between forage molecular structure and bio-functions. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Bio-functions and molecular carbohydrate structure association study in forage with different source origins revealed using non-destructive vibrational molecular spectroscopy techniques

    NASA Astrophysics Data System (ADS)

    Ji, Cuiying; Zhang, Xuewei; Yan, Xiaogang; Mostafizar Rahman, M.; Prates, Luciana L.; Yu, Peiqiang

    2017-08-01

    The objectives of this study were to: 1) investigate forage carbohydrate molecular structure profiles; 2) bio-functions in terms of CHO rumen degradation characteristics and hourly effective degradation ratio of N to OM (HEDN/OM), and 3) quantify interactive association between molecular structures, bio-functions and nutrient availability. The vibrational molecular spectroscopy was applied to investigate the structure feature on a molecular basis. Two sourced-origin alfalfa forages were used as modeled forages. The results showed that the carbohydrate molecular structure profiles were highly linked to the bio-functions in terms of rumen degradation characteristics and hourly effective degradation ratio. The molecular spectroscopic technique can be used to detect forage carbohydrate structure features on a molecular basis and can be used to study interactive association between forage molecular structure and bio-functions.

  15. Tracking Color Shift in Ballpoint Pen Ink Using Photoshop Assisted Spectroscopy: A Nondestructive Technique Developed to Rehouse a Nobel Laureate's Manuscript

    PubMed Central

    Wright, Kristi; Herro, Holly

    2016-01-01

    Many historically and culturally significant documents from the mid-to-late twentieth century were written in ballpoint pen inks, which contain light-sensitive dyes that present problems for collection custodians and paper conservators. The conservation staff at the National Library of Medicine (NLM), National Institutes of Health, conducted a multiphase project on the chemistry and aging of ballpoint pen ink that culminated in the development of a new method to detect aging of ballpoint pen ink while examining a variety of storage environments. NLM staff determined that ballpoint pen ink color shift can be detected noninvasively using image editing software. Instructions are provided on how to detect color shift in digitized materials using a technique developed specifically for this project—Photoshop Assisted Spectroscopy.1 The study results offer collection custodians storage options for historic documents containing ballpoint pen ink. PMID:27587904

  16. Further development of ultrasonic techniques for non-destructive evaluation based on Fourier analysis of signals from irregular and inhomogeneous structures

    NASA Technical Reports Server (NTRS)

    Miller, J. G.

    1979-01-01

    To investigate the use of Fourier analysis techniques model systems had to be designed to test some of the general properties of the interaction of sound with an inhomogeneity. The first models investigated were suspensions of solid spheres in water. These systems allowed comparison between theoretical computation of the frequency dependence of the attenuation coefficient and measurement of the attenuation coefficient over a range of frequencies. Ultrasonic scattering processes in both suspensions of hard spheres in water, and suspensions of hard spheres in polyester resin were investigated. The second model system was constructed to test the applicability of partial wave analysis to the description of an inhomogeneity in a solid, and to test the range of material properties over which the measurement systems were valid.

  17. Analytical investigation of Mudéjar polychrome on the carpentry in the Casa de Pilatos palace in Seville using non-destructive XRF and complementary techniques.

    PubMed

    Garrote, M A; Robador, M D; Perez-Rodriguez, J L

    2017-02-15

    The pigments, execution technique and repainting used on the polychrome wood ceilings and doors in the Casa de Pilatos (Seville, Spain) were studied using portable X-ray fluorescence equipment. Cross-sections of small samples were also analysed by optical microscopy, SEM with EDX analysis, micro-Raman and micro-infrared spectroscopy and X-ray diffraction. These carpentry works are magnificent examples of the Mudéjar art made in Spain in the early 16th century. Portable X-ray fluorescence gave good information on the different components of the polychrome. The SEM-EDX study of the surfaces of small samples gave information on their components and also characterized the compounds that had been deposited or formed by environmental contamination or by the alteration of some pigments. The SEM-EDX study of cross-sections facilitated the characterization of all layers and pigments from the support to the most external layer. The following pigments were characterized: red (cinnabar/vermillion, lead oxide, iron oxides and orpiment/realgar), black (carbon black), white (white lead and titanium barium white), yellow-orange-red-brown (orpiment/realgar and iron oxides), green (chromium oxide), blue (indigo blue and ultramarine blue), and gilding (gold leaf on bole). False gold, bronze and brass were also found. The pigments were applied with the oil painting technique over a support layer that had been primed with animal glue. This support layer was gypsum in some cases and white lead in others. This study is essential to the polychrome conservation of the studied artwork, and it will help clarify uncertainties in the history and painting of Mudéjar art.

  18. Analytical investigation of Mudéjar polychrome on the carpentry in the Casa de Pilatos palace in Seville using non-destructive XRF and complementary techniques

    NASA Astrophysics Data System (ADS)

    Garrote, M. A.; Robador, M. D.; Perez-Rodriguez, J. L.

    2017-02-01

    The pigments, execution technique and repainting used on the polychrome wood ceilings and doors in the Casa de Pilatos (Seville, Spain) were studied using portable X-ray fluorescence equipment. Cross-sections of small samples were also analysed by optical microscopy, SEM with EDX analysis, micro-Raman and micro-infrared spectroscopy and X-ray diffraction. These carpentry works are magnificent examples of the Mudéjar art made in Spain in the early 16th century. Portable X-ray fluorescence gave good information on the different components of the polychrome. The SEM-EDX study of the surfaces of small samples gave information on their components and also characterized the compounds that had been deposited or formed by environmental contamination or by the alteration of some pigments. The SEM-EDX study of cross-sections facilitated the characterization of all layers and pigments from the support to the most external layer. The following pigments were characterized: red (cinnabar/vermillion, lead oxide, iron oxides and orpiment/realgar), black (carbon black), white (white lead and titanium barium white), yellow-orange-red-brown (orpiment/realgar and iron oxides), green (chromium oxide), blue (indigo blue and ultramarine blue), and gilding (gold leaf on bole). False gold, bronze and brass were also found. The pigments were applied with the oil painting technique over a support layer that had been primed with animal glue. This support layer was gypsum in some cases and white lead in others. This study is essential to the polychrome conservation of the studied artwork, and it will help clarify uncertainties in the history and painting of Mudéjar art.

  19. Non-destructive determination of maize leaf and canopy chlorophyll content

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to develop a rapid non-destructive technique to estimate total chlorophyll (Chl) content in a maize canopy using Chl content in a single leaf. The approach was (1) to calibrate and validate a reflectance-based non-destructive technique to estimate leaf Chl in maize; (...

  20. Quantitative non-destructive evaluation of composite materials based on ultrasonic wave propagation

    NASA Technical Reports Server (NTRS)

    Miller, J. G.

    1986-01-01

    The application and interpretation of specific ultrasonic nondestructive evaluation techniques are studied. The Kramers-Kronig or generalized dispersion relationships are applied to nondestructive techniques. Progress was made on an improved determination of material properties of composites inferred from elastic constant measurements.

  1. Assessment of Microstructure in Grade T22 Cr-Mo Steel by Nondestructive Tools

    NASA Astrophysics Data System (ADS)

    Kiattisaksri, P.; Meir, S.; Poncelow, J.; Madeni, J. C.; Hellner, R. L.; Coleman, K.; Liu, S.; Mishra, B.; Olson, D. L.

    2011-06-01

    Nondestructive techniques are being developed for rapid inspection to estimate the remaining service life for power generating plants. Low frequency impedance measurements with ultrasonic resonant wave enhancement to evaluate the precipitation of carbides and to characterize the different microstructures during aging are being developed. The simultaneous use of a combination of two nondestructive techniques for assessing microstructure evolution is illustrated.

  2. Nondestructive evaluation of pyroshock propagation using hydrocodes

    NASA Astrophysics Data System (ADS)

    Lee, Juho; Hwang, Dae-Hyeon; Jang, Jae-Kyeong; Lee, Jung-Ryul; Han, Jae-Hung

    2016-04-01

    Pyroshock or pyrotechnic shock generated by explosive events of pyrotechnic devices can induce fatal failures in electronic payloads. Therefore, understanding and estimation of pyroshock propagation through complex structures are necessary. However, an experimental approach using real pyrotechnic devices is quite burdensome because pyrotechnic devices can damage test structures and newly manufactured test structures are necessary for each experiment. Besides, pyrotechnic experiments are quite expensive, time-consuming, and dangerous. Consequently, nondestructive evaluation (NDE) of pyroshock propagation without using real pyrotechnic devices is necessary. In this study, nondestructive evaluation technique for pyroshock propagation estimation using hydrocodes is proposed. First, pyroshock propagation is numerically analyzed using AUTODYN, a commercial hydrocodes. Hydrocodes can handle stress wave propagation including elastic, plastic, and shock wave in the time domain. Test structures are modeled and pyroshock time history is applied to where the pyroshock propagation originates. Numerical NDE results of pyroshock propagation on test structures are analyzed in terms of acceleration time histories and acceleration shock response spectra (SRS) results. To verify the proposed numerical methodology, impact tests using airsoft gun are performed. The numerical analysis results for the impact tests are compared with experimental results and they show good agreements. The proposed numerical techniques enable us to nondestructively characterize pyroshock propagation.

  3. On the distribution of uranium in hair: Non-destructive analysis using synchrotron radiation induced X-ray fluorescence microprobe techniques

    NASA Astrophysics Data System (ADS)

    Israelsson, A.; Eriksson, M.; Pettersson, H. B. L.

    2015-06-01

    In the present study the distribution of uranium in single human hair shafts has been evaluated using two synchrotron radiation (SR) based micro X-ray fluorescence techniques; SR μ-XRF and confocal SR μ-XRF. The hair shafts originated from persons that have been exposed to elevated uranium concentrations. Two different groups have been studied, i) workers at a nuclear fuel fabrication factory, exposed mainly by inhalation and ii) owners of drilled bedrock wells exposed by ingestion of water. The measurements were carried out on the FLUO beamline at the synchrotron radiation facility ANKA, Karlsruhe. The experiment was optimized to detect U with a beam size of 6.8 μm × 3 μm beam focus allowing detection down to ppb levels of U in 10 s (SR μ-XRF setup) and 70 s (SR confocal μ-XRF setup) measurements. It was found that the uranium was present in a 10-15 μm peripheral layer of the hair shafts for both groups studied. Furthermore, potential external hair contamination was studied by scanning of unwashed hair shafts from the workers. Sites of very high uranium signal were identified as particles containing uranium. Such particles, were also seen in complementary analyses using variable pressure electron microscope coupled with energy dispersive X-ray analyzer (ESEM-EDX). However, the particles were not visible in washed hair shafts. These findings can further increase the understanding of uranium excretion in hair and its potential use as a biomonitor.

  4. Biospeckle technique for the non-destructive differentiation of bruised and fresh regions of an Indian apple using intensity-based algorithms

    NASA Astrophysics Data System (ADS)

    Kumari, S.; Nirala, A. K.

    2016-11-01

    In the present paper intensity-based algorithms have been applied to differentiate the bruised and fresh regions of an Indian apple through biospeckle technique during its 9 day shelf life. Existing algorithms such as the co-occurrence matrix, inertia moment, absolute value difference, generalized difference, parameterized Fujii, biospeckle activity (BA) value, granulometric size distribution (GSD) and grey-level co-occurrence matrix (GLCM), as well as three new proposed algorithms namely parameterized generalized difference, alternative generalized difference (AGD) and parameterized global average Fujii, have been used for qualitative and quantitative analysis. Co-occurrence matrix and activity level spectral maps have been used for qualitative analysis, whereas mean activity plots, curve of the BA index, GSD plots and texture features have been used for quantitative analysis. The experimental results suggest that overall difference in biospeckle activity between the bruised and fresh regions is maximum for the inertia moment method (521.99). Of the three proposed algorithms AGD gives the maximum overall difference in biospeckle activity (42.35). In addition, the BA value and parameters of the GLCM have also been applied for the first time to distinguish between the bruised and fresh regions of an Indian apple, and it is concluded that both the methods may be used for good differentiation between the bruised and fresh regions of apples.

  5. In situ Raman spectroscopy and confocal microscopy of 2.5-billion-year-old fossil microorganisms: viable nondestructive techniques for the study of returned Martian samples

    NASA Astrophysics Data System (ADS)

    Calvin, W. M.; Fraeman, A.; Ehlmann, B. L.; Lautze, N. C.

    2014-12-01

    The Humu'ula Groundwater Research Project (HGRP) drilled their first continuously-cored hole in the saddle region of the big island of Hawaii in March of 2013. Temperatures at the bottom of the hole were unexpectedly high and reached over 100C. The core traverses various lava flows, representing the shield-building phase of the island and the lithology is dominantly basalt with varying amounts of plagioclase and olivine phenocrysts. Logging of the core noted that discontinuous alteration became prevalent starting at ~ 1 km depth. In May of 2015 we collected 780 infrared spectra of the core from depths of 0.97 to 1.76 km using our portable field spectrometer with a contact probe and field of view of 10 mm. Many of the spectra are unaltered, showing mafic mineralogy (augite or augite with olivine). Minerals from aqueous alteration include clinochlore, micaceous minerals likely mixed with other common phyllic alteration products, and three groups of spectral types associated with zeolites. This suite of minerals suggests alteration was initiated from higher temperature and moderate pH fluids. Based on the field reconnaissance spectroscopy, 25 sections were cut that represent the alteration diversity for thin section and subsequent detailed petrologic analyses. Eight of these sections were examined using the Ultra-Compact Imaging Spectrometer (UCIS) prototype instrument at the Jet Propulsion Laboratory. UCIS collects spectra at 80 μm / pixel and identifies the same alteration mineralogy as the bulk samples, but clearly shows that the alteration occurs in veins and vugs. Unaltered olivine and pyroxene phenocrysts occur in the groundmass adjacent to highly altered vugs, and are preserved throughout the section surveyed. Given the limited alteration and abundant preservation of olivine to depths of 1.5 km, the core may be representative of alteration in moderate pH environments on Mars, where unaltered basaltic materials occur in close proximity to alteration products

  6. Nondestructive evaluation by acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1988-01-01

    Acousto-ultrasonics is an ultrasonic technique that was originally devised to cope with the particular problems associated with nondestructive evaluation (NDE) of fiber/polymer composite structures. The fiber/polymer composites are more attenuating to ultrasound than any other material presently of interest. This limits the applicability of high-frequency ultrasonics. A common use of ultrasound is the imaging of flaws internal to a structure by scattering from the interface with the flaw. However, structural features of composites can scatter ultrasound internally, thus obscuring the flaws. A need relative to composites is to be able to nondestructively measure the strength of laminar boundaries in order to assess the integrity of a structure. Acousto-ultrasonics has exhibited the ability to use the internal scattering to provide information for determining the strength of laminar boundaries. Analysis of acousto-ultrasonic signals by the wave ray paths that compose it leads to waveform partitioning that enhances the sensitivity to mechanical strength parameters.

  7. Nondestructive Test Probe

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Under the Aircraft Structural Integrity program, Langley Research Center invented a device to detect fatigue cracks in aluminum alloy plates. Krautkramer Branson obtained an exclusive license and commercialized a hand-held device, the "CrackFinder," an electromagnetic probe for nondestructive evaluation, used to scan aircraft skins for surface breaks. The technology involves an eddy current, which is an electrical current induced by an alternating magnetic field. The CrackFinder also employs an innovative self-nulling feature, where the device automatically recalibrates to zero so that each flaw detected produces a reading. Compared to conventional testing systems, the CrackFinder is affordable, small, simple to use, and needs no calibration.

  8. Non-destructive micro-analytical differentiation of copper pigments in paint layers of works of art using laboratory-based techniques.

    PubMed

    Svarcová, Silvie; Cermáková, Zdeňka; Hradilová, Janka; Bezdička, Petr; Hradil, David

    2014-11-11

    An unambiguous identification of pigments in paint layers of works of art forms a substantial part of the description of a painting technique, which is essential for the evaluation of the work of art including determination of the period and/or region of its creation as well as its attribution to a workshop or an author. Copper pigments represent a significant group of materials used in historic paintings. Because of their substantial diversity and, on the other hand, similarity, their identification and differentiation is a challenging task. An analytical procedure for unambiguous determination of both mineral-type (azurite, malachite, posnjakite, atacamite, etc.) and verdigris-type (copper acetates) copper pigments in the paint layers is presented, including light microscopy under VIS and UV light, electron microscopy with elemental microanalysis, Fourier transformed infrared micro-spectroscopy (micro-FTIR), and X-ray powder micro-diffraction (micro-XRD). Micro-Raman measurements were largely hindered by fluorescence. The choice of the analytical methods meets the contemporary requirement of a detailed description of various components in heterogeneous and minute samples of paint layers without their destruction. It is beneficial to use the combination of phase sensitive methods such as micro-FTIR and micro-XRD, because it allows the identification of both mineral-type and verdigris-type copper pigments in one paint layer. In addition, preliminary results concerning the study of the loss of crystallinity of verdigris-type pigments in proteinaceous binding media and the effect of lead white and lead tin yellow as highly absorbing matrix on verdigris identification in paint layers are reported.

  9. Non-destructive micro-analytical differentiation of copper pigments in paint layers of works of art using laboratory-based techniques

    NASA Astrophysics Data System (ADS)

    Švarcová, Silvie; Čermáková, Zdeňka; Hradilová, Janka; Bezdička, Petr; Hradil, David

    2014-11-01

    An unambiguous identification of pigments in paint layers of works of art forms a substantial part of the description of a painting technique, which is essential for the evaluation of the work of art including determination of the period and/or region of its creation as well as its attribution to a workshop or an author. Copper pigments represent a significant group of materials used in historic paintings. Because of their substantial diversity and, on the other hand, similarity, their identification and differentiation is a challenging task. An analytical procedure for unambiguous determination of both mineral-type (azurite, malachite, posnjakite, atacamite, etc.) and verdigris-type (copper acetates) copper pigments in the paint layers is presented, including light microscopy under VIS and UV light, electron microscopy with elemental microanalysis, Fourier transformed infrared micro-spectroscopy (micro-FTIR), and X-ray powder micro-diffraction (micro-XRD). Micro-Raman measurements were largely hindered by fluorescence. The choice of the analytical methods meets the contemporary requirement of a detailed description of various components in heterogeneous and minute samples of paint layers without their destruction. It is beneficial to use the combination of phase sensitive methods such as micro-FTIR and micro-XRD, because it allows the identification of both mineral-type and verdigris-type copper pigments in one paint layer. In addition, preliminary results concerning the study of the loss of crystallinity of verdigris-type pigments in proteinaceous binding media and the effect of lead white and lead tin yellow as highly absorbing matrix on verdigris identification in paint layers are reported.

  10. Analytical techniques: A compilation

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A compilation, containing articles on a number of analytical techniques for quality control engineers and laboratory workers, is presented. Data cover techniques for testing electronic, mechanical, and optical systems, nondestructive testing techniques, and gas analysis techniques.

  11. Nondestructive measurement of environmental radioactive strontium

    NASA Astrophysics Data System (ADS)

    Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Totsuka, Yumi; Murata, Jiro

    2014-03-01

    The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days), Cs-134 (2.1 years), Cs-137 (30 years), Sr-89 (51 days), and Sr-90 (29 years). We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.

  12. Quantitative nondestructive evaluation of materials and structures

    NASA Technical Reports Server (NTRS)

    Smith, Barry T.

    1991-01-01

    An experimental investigation was undertaken to quantify damage tolerance and resistance in composite materials impacted using the drop-weight method. Tests were conducted on laminates of several different carbon-fiber composite systems, such as epoxies, modified epoxies, and amorphous and semicrystalline thermoplastics. Impacted composite specimens were examined using destructive and non-destructive techniques to establish the characteristic damage states. Specifically, optical microscopy, ultrasonic, and scanning electron microscopy techniques were used to identify impact induced damage mechanisms. Damage propagation during post impact compression was also studied.

  13. Use of structured personality survey techniques to indicate operator response to stressful situations

    SciTech Connect

    Waller, M.A.

    1990-01-01

    Under given circumstances, a person will tend to operate in one of four dominant orientations: (1) to perform tasks; (2) to achieve consensus; (3) to achieve understanding, or (4) to maintain structure. Historically, personality survey techniques, such as the Myers-Briggs type indicator, have been used to determine these tendencies. While these techniques can accurately reflect a person's orientation under normal social situations, under different sets of conditions, the same person may exhibit other tendencies, displaying a similar or entirely different orientation. While most do not exhibit extreme tendencies or changes of orientation, the shift in personality from normal to stressful conditions can be rather dramatic, depending on the individual. Structured personality survey techniques have been used to indicate operator response to stressful situations. These techniques have been extended to indicate the balance between orientations that the control room team has through the various levels of cognizance.

  14. Nondestructive Characterization of Aged Components

    SciTech Connect

    Panetta, Paul D.; Toloczko, Mychailo B.; Garner, Francis A.; Balachov, Iouri I.

    2003-10-21

    It is known that high energy radiation can have numerous effects on materials. In metals and alloys, the effects include, but may not be limited to, mechanical property changes, physical property changes, compositional changes, phase changes, and dimensional changes. Metals and alloys which undergo high energy self-irradiation are also susceptible to these changes. One of the greatest concerns with irradiation of materials is the phenomenon of void swelling which has been observed in a wide variety of metals and alloys. Irradiation causes the formation of a high concentration point defects and microclusters of vacancies and interstitials. With the assistance of an inert atom such as helium, the vacancy-type defects can coalesce to form a stable bubble. This bubble will continue to grow through the net absorption of more vacancy-type defects and helium atoms, and upon reaching a certain critical size, the bubble will begin to grow at an accelerated rate without the assistance of inert atom absorption. The bubble is then said to be an unstably growing void. Depending on the alloy system and environment, swelling values can reach in excess of 50% !V/Vo where Vo is the initial volume of the material. Along with dimensional changes resulting from the formation of bubbles and voids comes changes in the macroscopically observed speed of sound, moduli, electrical resistivity, yield strength, and other properties. These effects can be detrimental to the designed operation of the aged components. In situations where irradiation has sufficient time to cause degradation to materials used in critical applications such as nuclear reactor core structural materials, it is advisable to regularly survey the material properties. It is common practice to use surveillance specimens, but this is not always possible. When surveillance materials are not available, other means for surveying the material properties must be utilized. Sometimes it is possible to core out a small sample which

  15. Ultrasonic Nondestructive Characterization of Porous Materials

    NASA Astrophysics Data System (ADS)

    Yang, Ningli

    2011-12-01

    Wave propagation in porous media is studied in a wide range of technological applications. In the manufacturing industry, determining porosity of materials in the manufacturing process is required for strict quality control. In the oil industry, acoustic signals and seismic surveys are used broadly to determine the physical properties of the reservoir rock which is a porous media filled with oil or gas. In porous noise control materials, a precise prediction of sound absorption with frequency and evaluation of tortuosity are necessary. Ultrasonic nondestructive methods are a very important tool for characterization of porous materials. The dissertation deals with two types of porous media: materials with relatively low and closed porosity and materials with comparatively high and open porosity. Numerical modeling, Finite Element simulations and experimental characterization are all discussed in this dissertation. First, ultrasonic scattering is used to determine the porosity in porous media with closed pores. In order get a relationship between the porosity in porous materials and ultrasonic scattering independently and to increase the sensitivity to obtain scattering information, ultrasonic imaging methods are applied and acoustic waves are focused by an acoustic lens. To verify the technique, engineered porous acrylic plates with varying porosity are measured by ultrasonic scanning and ultrasonic array sensors. Secondly, a laser based ultrasonic technique is explored for predicting the mechanical integrity and durability of cementitious materials. The technique used involves the measurement of the phase velocity of fast and slow longitudinal waves in water saturated cement paste. The slow wave velocity is related to the specimen's tortuosity. The fast wave speed is dependent on the elastic properties of porous solid. Experimental results detailing the generation and detection of fast and slow wave waves in freshly prepared and aged water-saturated cement samples

  16. Development of instrumentation for magnetic nondestructive evaluation

    SciTech Connect

    Hariharan, S.

    1991-09-23

    The use of failure-prone components in critical applications has been traditionally governed by removing such components from service prior to the expiration of their predicted life expectancy. Such early retirement of materials does not guarantee that a particular sample will not fail in actual usage. The increasing cost of such life expectancy based operation and increased demand for improved reliability in industrial settings has necessitated an alternate form of quality control. Modern applications employ nondestructive evaluation (NDE), also known as nondestructive testing (NDT), as a means of monitoring the levels and growth of defects in a material throughout its operational life. This thesis describes the modifications made to existing instrumentation used for magnetic measurements at the Center for Nondestructive Evaluation at Iowa State University. Development of a new portable instrument is also given. An overview of the structure and operation of this instrumentation is presented. This thesis discusses the application of the magnetic hysteresis and Barkhausen measurement techniques, described in Sections 1.3.1 and 1.3.2 respectively, to a number of ferromagnetic specimens. Specifically, measurements were made on a number of railroad steel specimens for fatigue characterization, and on specimens of Damascus steel and Terfenol-D for materials evaluation. 60 refs., 51 figs., 5 tabs.

  17. Nondestructive Evaluation of Adhesively Bonded Joints

    NASA Technical Reports Server (NTRS)

    Nayeb-Hashemi, Hamid; Rossettos, J. N.

    1997-01-01

    The final report consists of 5 published papers in referred journals and a technical letter to the technical monitor. These papers include the following: (1) Comparison of the effects of debonds and voids in adhesive; (2) On the peak shear stresses in adhesive joints with voids; (3) Nondestructive evaluation of adhesively bonded joints by acousto-ultrasonic technique and acoustic emission; (4) Multiaxial fatigue life evaluation of tubular adhesively bonded joints; (5) Theoretical and experimental evaluation of the bond strength under peeling loads. The letter outlines the progress of the research. Also included is preliminary information on the study of nondestructive evaluation of composite materials subjected to localized heat damage. The investigators studied the effects of localized heat on unidirectional fiber glass epoxy composite panels. Specimens of the fiber glass epoxy composites were subjected to 400 C heat for varying lengths of time. The specimens were subjected to nondestructive tests. The specimens were then pulled to their failure and acoustic emission of these specimens were measured. The analysis of the data was continuing as of the writing of the letter, and includes a finite element stress analysis of the problem.

  18. A Survey of the Practices, Procedures, and Techniques in Undergraduate Organic Chemistry Teaching Laboratories

    ERIC Educational Resources Information Center

    Martin, Christopher B.; Schmidt, Monica; Soniat, Michael

    2011-01-01

    A survey was conducted of four-year institutions that teach undergraduate organic chemistry laboratories in the United States. The data include results from over 130 schools, describes the current practices at these institutions, and discusses the statistical results such as the scale of the laboratories performed, the chemical techniques applied,…

  19. A Survey of the Practices, Procedures, and Techniques in Undergraduate Organic Chemistry Teaching Laboratories

    ERIC Educational Resources Information Center

    Martin, Christopher B.; Schmidt, Monica; Soniat, Michael

    2011-01-01

    A survey was conducted of four-year institutions that teach undergraduate organic chemistry laboratories in the United States. The data include results from over 130 schools, describes the current practices at these institutions, and discusses the statistical results such as the scale of the laboratories performed, the chemical techniques applied,…

  20. Nondestructive Determination of Bond Strength

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Although many nondestructive techniques have been applied to detect disbonds in adhesive joints, no absolutely reliable nondestructive method has been developed to detect poor adhesion and evaluate the strength of bonded joints prior to the present work which used nonlinear ultrasonic methods to investigate adhesive bond cure conditions. Previously, a variety of linear and nonlinear ultrasonic methods with water coupling had been used to study aluminum-adhesive-aluminum laminates, prepared under different adhesive curing conditions, for possible bond strength determination. Therefore, in the course of this research effort, a variety of finite-amplitude experimental methods which could possibly differentiate various cure conditions were investigated, including normal and oblique incidence approaches based on nonlinear harmonic generation as well as several non-collinear two-wave interaction approaches. Test samples were mechanically scanned in various ways with respect to the focus of a transmitting transducer operated at several variable excitation frequencies and excitation levels. Even when powerful sample-related resonances were exploited by means of a frequency scanning approach, it was very difficult to isolate the nonlinear characteristics of adhesive bonds. However, a multi-frequency multi-power approach was quite successful and reliable. Ultrasonic tone burst signals at increasing power levels, over a wide frequency range, were transmitted through each bond specimen to determine its excitation dependent nonlinear harmonic resonance behavior. Relative amplitude changes were observed particularly in the higher harmonic spectral data and analyzed using a local displacement and strain analysis in the linear approximation. Two analysis approaches of the excitation-dependent data at specific resonances were found to be quite promising. One of these approaches may represent a very robust algorithm for classifying an adhesive bond as being properly cured or not

  1. Evaluation of nondestructive tensile testing

    NASA Technical Reports Server (NTRS)

    Bowe, J. J.; Polcari, S. M.

    1971-01-01

    The results of a series of experiments performed in the evaluation of nondestructive tensile testing of chip and wire bonds are presented. Semiconductor devices were subjected to time-temperature excursions, static-load life testing and multiple pre-stressing loads to determine the feasibility of a nondestructive tensile testing approach. The report emphasizes the importance of the breaking angle in determining the ultimate tensile strength of a wire bond, a factor not generally recognized nor implemented in such determinations.

  2. Dynamics-based Nondestructive Structural Monitoring Techniques

    DTIC Science & Technology

    2012-06-21

    analytical model. Cesnik and his colleagues have developed wedge-shaped guided wave SHM transducers with interdigital sector elements, called CLoVER...finished electrodes are shown in Figure 4.2. Two 42 mm diameter disks and two 30 mm diameter disks were used in the fabrication. The electrode ...on one small disk. The other small disk has 4 segments with each segment having 4 fan- shaped electrodes . All individual electrode elements of the 4

  3. Evaluation of Nondestructive Underwater Timber Inspection Techniques

    DTIC Science & Technology

    1984-08-01

    possible to codice their presnce. Figure 1. Characteristics of marine borers. 3 Table 1. Accuracy Requirements for Timber Piles [Nomenclature at end of...Athens GA NAVSEASYSCOM Code OOC-D. Washington. DC: Codk PMS 395 A 3. Washington. DC; Code PMS 395 A2. Wasi~ington. DC; Codic PMS 396.3311 (Rekas), Wash...HI NEW MEXICO SOLAR ENERGY INST. Dr. Zwibel Las Cruces NM NORTHWESTERN UNIV Z.P. Bazant Evanston IL NY CITY COMMUNITY COLLEGE BROOKLYN. NY (LIBRARY

  4. An Instructional Program for Training Nondestructive Testing and Inspection Technicians.

    ERIC Educational Resources Information Center

    Stokes, Vernon L.

    This document, the second portion of a two-part study, is designed to provide a guide for the formal training of technicians for nondestructive testing and inspection. Information in the guide is based on results of the industrial survey discussed in Part I. The subject matter is intended to be both flexible and comprehensive, and instructional…

  5. Preliminary nondestructive evaluation manual for the space shuttle. [preliminary nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Pless, W. M.

    1974-01-01

    Nondestructive evaluation (NDE) requirements are presented for some 134 potential fracture-critical structural areas identified, for the entire space shuttle vehicle system, as those possibly needing inspection during refurbishment/turnaround and prelaunch operations. The requirements include critical area and defect descriptions, access factors, recommended NDE techniques, and descriptive artwork. Requirements discussed include: Orbiter structure, external tank, solid rocket booster, and thermal protection system (development area).

  6. Visual servoing in medical robotics: a survey. Part II: tomographic imaging modalities--techniques and applications.

    PubMed

    Azizian, Mahdi; Najmaei, Nima; Khoshnam, Mahta; Patel, Rajni

    2015-03-01

    Intraoperative application of tomographic imaging techniques provides a means of visual servoing for objects beneath the surface of organs. The focus of this survey is on therapeutic and diagnostic medical applications where tomographic imaging is used in visual servoing. To this end, a comprehensive search of the electronic databases was completed for the period 2000-2013. Existing techniques and products are categorized and studied, based on the imaging modality and their medical applications. This part complements Part I of the survey, which covers visual servoing techniques using endoscopic imaging and direct vision. The main challenges in using visual servoing based on tomographic images have been identified. 'Supervised automation of medical robotics' is found to be a major trend in this field and ultrasound is the most commonly used tomographic modality for visual servoing. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Nondestructive Evaluation of Nuclear-Grade Graphite

    SciTech Connect

    Dennis C. Kunerth; Timothy R. McJunkin

    2011-07-01

    Nondestructive Evaluation of Nuclear Grade Graphite Dennis C. Kunerth and Timothy R. McJunkin Idaho National Laboratory Idaho Falls, ID, 83415 This paper discusses the nondestructive evaluation of nuclear grade graphite performed at the Idaho National Laboratory. Graphite is a composite material highly dependent on the base material and manufacturing methods. As a result, material variations are expected within individual billets as well billet to billet and lot to lot. Several methods of evaluating the material have been explored. Particular technologies each provide a subset of information about the material. This paper focuses on techniques that are applicable to in-service inspection of nuclear energy plant components. Eddy current examination of the available surfaces provides information on potential near surface structural defects and although limited, ultrasonics can be utilized in conventional volumetric inspection. Material condition (e.g. micro-cracking and porosity induced by radiation and stress) can be derived from backscatter or acousto-ultrasound (AU) methods. Novel approaches utilizing phased array ultrasonics have been attempted to expand the abilities of AU techniques. By combining variable placement of apertures, angle and depth of focus, the techniques provide the potential to obtain parameters at various depths in the material. Initial results of the study and possible procedures for application of the techniques are discussed.

  8. Nondestructive Assay Options for Spent Fuel Encapsulation

    SciTech Connect

    Tobin, Stephen J.; Jansson, Peter

    2014-10-02

    This report describes the role that nondestructive assay (NDA) techniques and systems of NDA techniques may have in the context of an encapsulation and deep geological repository. The potential NDA needs of an encapsulation and repository facility include safeguards, heat content, and criticality. Some discussion of the facility needs is given, with the majority of the report concentrating on the capability and characteristics of individual NDA instruments and techniques currently available or under development. Particular emphasis is given to how the NDA techniques can be used to determine the heat production of an assembly, as well as meet the dual safeguards needs of 1) determining the declared parameters of initial enrichment, burn-up, and cooling time and 2) detecting defects (total, partial, and bias). The report concludes with the recommendation of three integrated systems that might meet the combined NDA needs of the encapsulation/repository facility.

  9. Characterization of Nitinol Laser-Weld Joints by Nondestructive Testing

    NASA Astrophysics Data System (ADS)

    Wohlschlögel, Markus; Gläßel, Gunter; Sanchez, Daniela; Schüßler, Andreas; Dillenz, Alexander; Saal, David; Mayr, Peter

    2015-12-01

    Joining technology is an integral part of today's Nitinol medical device manufacturing. Besides crimping and riveting, laser welding is often applied to join components made from Nitinol to Nitinol, as well as Nitinol components to dissimilar materials. Other Nitinol joining techniques include adhesive bonding, soldering, and brazing. Typically, the performance of joints is assessed by destructive mechanical testing, on a process validation base. In this study, a nondestructive testing method—photothermal radiometry—is applied to characterize small Nitinol laser-weld joints used to connect two wire ends via a sleeve. Two different wire diameters are investigated. Effective joint connection cross sections are visualized using metallography techniques. Results of the nondestructive testing are correlated to data from destructive torsion testing, where the maximum torque at fracture is evaluated for the same joints and criteria for the differentiation of good and poor laser-welding quality by nondestructive testing are established.

  10. Objective measures, sensors and computational techniques for stress recognition and classification: a survey.

    PubMed

    Sharma, Nandita; Gedeon, Tom

    2012-12-01

    Stress is a major growing concern in our day and age adversely impacting both individuals and society. Stress research has a wide range of benefits from improving personal operations, learning, and increasing work productivity to benefiting society - making it an interesting and socially beneficial area of research. This survey reviews sensors that have been used to measure stress and investigates techniques for modelling stress. It discusses non-invasive and unobtrusive sensors for measuring computed stress, a term we coin in the paper. Sensors that do not impede everyday activities that could be used by those who would like to monitor stress levels on a regular basis (e.g. vehicle drivers, patients with illnesses linked to stress) is the focus of the discussion. Computational techniques have the capacity to determine optimal sensor fusion and automate data analysis for stress recognition and classification. Several computational techniques have been developed to model stress based on techniques such as Bayesian networks, artificial neural networks, and support vector machines, which this survey investigates. The survey concludes with a summary and provides possible directions for further computational stress research.

  11. Microwave sensors for nondestructive testing of materials

    NASA Astrophysics Data System (ADS)

    Lasri, Tuami; Glay, David; Mamouni, Ahmed; Leroy, Yves

    1999-10-01

    Much of today's applications in nondestructive testing by microwaves use an automatic network analyzer. As a result, there is a need for systems to reduce the cost of this kind of techniques. Fortunately, now we can benefit from the cost reduction of the microwave components, induced by the considerable development of the communication market, around 2 and 10 GHz. So, it seems reasonable to think that microwaves will take advantage of this new situation to assert themselves in this application field. In this context we conceive and develop original equipment competitive in term of price and reliability.

  12. Nondestructive assay confirmatory assessment experiments: mixed oxide

    SciTech Connect

    Lemming, J.F.

    1980-04-30

    The confirmatory assessment experiments demonstrate traceable nondestructive assay (NDA) measurements of plutonium in mixed oxide powder using commercially available spontaneous-fission assay systems. The experiments illustrate two major concepts: the production of calibration materials using calorimetric assay, and the use of paired measurements for measurement assurance. Two batches of well-characterized mixed oxide powder were used to establish the random and systematic error components. The major components of an NDA measurement assurance technique to establish and maintain traceability are identified and their functions are demonstrated. 20 refs., 10 figs., 10 tabs.

  13. D Survey Techniques for the Architectutal Restoration: the Case of ST. Agata in Pisa

    NASA Astrophysics Data System (ADS)

    Bevilacqua, M. G.; Caroti, G.; Piemonte, A.; Ruschi, P.; Tenchini, L.

    2017-05-01

    The historical architectural heritage may be considered as the product of a complex system of interaction between several factors - cultural, socio-economic, technical, aesthetic etc. The restoration and conservation of this important heritage, therefore, requires necessarily a multidisciplinary approach, both in the preliminary phase of knowledge and in the operative one, strictly connected to the first, regarding the development of the restoration works in all their steps, from the project to the realization. The historical-critical analysis of bibliographic, archival and iconographic sources, together with the architectural survey, aims at interpreting all the events that, from the initial project to all the eventual phases of transformation, have lead the monument in its current state. This is therefore a multi-temporal and multi-spatial study in which geomatics gives an innovative contribution for its capability of gathering, storing, processing, and delivering different levels of spatially referenced information. The current techniques of architectural survey, supported by specific methodological skills, are therefore not limited to a mere mathematical-geometrical description of the historical building, but are useful also for many other purposes, such as formal-linguistic analysis, interpretation of the historical phases of transformation, description of the state of degradation/conservation etc. In this interdisciplinary perspective, photogrammetry and laser scanner represent the two main techniques, as they offer the greatest potential of performing integrated surveys. In the last decades, we have witnessed the growth and development of these 3D-survey techniques as alternative or complementary tools to the traditional ones. In particular, in the field of architectural restoration, these techniques have made significant improvements not only in terms of measure precision or reduction of time for survey operations, but also for the possibility to represent

  14. A survey of techniques for architecting and managing GPU register file

    DOE PAGES

    Mittal, Sparsh

    2016-04-07

    To support their massively-multithreaded architecture, GPUs use very large register file (RF) which has a capacity higher than even L1 and L2 caches. In total contrast, traditional CPUs use tiny RF and much larger caches to optimize latency. Due to these differences, along with the crucial impact of RF in determining GPU performance, novel and intelligent techniques are required for managing GPU RF. In this paper, we survey the techniques for designing and managing GPU RF. We discuss techniques related to performance, energy and reliability aspects of RF. To emphasize the similarities and differences between the techniques, we classify themmore » along several parameters. Lastly, the aim of this paper is to synthesize the state-of-art developments in RF management and also stimulate further research in this area.« less

  15. A survey of techniques for architecting and managing GPU register file

    SciTech Connect

    Mittal, Sparsh

    2016-04-07

    To support their massively-multithreaded architecture, GPUs use very large register file (RF) which has a capacity higher than even L1 and L2 caches. In total contrast, traditional CPUs use tiny RF and much larger caches to optimize latency. Due to these differences, along with the crucial impact of RF in determining GPU performance, novel and intelligent techniques are required for managing GPU RF. In this paper, we survey the techniques for designing and managing GPU RF. We discuss techniques related to performance, energy and reliability aspects of RF. To emphasize the similarities and differences between the techniques, we classify them along several parameters. Lastly, the aim of this paper is to synthesize the state-of-art developments in RF management and also stimulate further research in this area.

  16. A Survey Of Techniques for Managing and Leveraging Caches in GPUs

    SciTech Connect

    Mittal, Sparsh

    2014-09-01

    Initially introduced as special-purpose accelerators for graphics applications, graphics processing units (GPUs) have now emerged as general purpose computing platforms for a wide range of applications. To address the requirements of these applications, modern GPUs include sizable hardware-managed caches. However, several factors, such as unique architecture of GPU, rise of CPU–GPU heterogeneous computing, etc., demand effective management of caches to achieve high performance and energy efficiency. Recently, several techniques have been proposed for this purpose. In this paper, we survey several architectural and system-level techniques proposed for managing and leveraging GPU caches. We also discuss the importance and challenges of cache management in GPUs. The aim of this paper is to provide the readers insights into cache management techniques for GPUs and motivate them to propose even better techniques for leveraging the full potential of caches in the GPUs of tomorrow.

  17. A Methodological Intercomparison of Topographic and Aerial Photographic Habitat Survey Techniques

    NASA Astrophysics Data System (ADS)

    Bangen, S. G.; Wheaton, J. M.; Bouwes, N.

    2011-12-01

    A severe decline in Columbia River salmonid populations and subsequent Federal listing of subpopulations has mandated both the monitoring of populations and evaluation of the status of available habitat. Numerous field and analytical methods exist to assist in the quantification of the abundance and quality of in-stream habitat for salmonids. These methods range from field 'stick and tape' surveys to spatially explicit topographic and aerial photographic surveys from a mix of ground-based and remotely sensed airborne platforms. Although several previous studies have assessed the quality of specific individual survey methods, the intercomparison of competing techniques across a diverse range of habitat conditions (wadeable headwater channels to non-wadeable mainstem channels) has not yet been elucidated. In this study, we seek to enumerate relative quality (i.e. accuracy, precision, extent) of habitat metrics and inventories derived from an array of ground-based and remotely sensed surveys of varying degrees of sophistication, as well as quantify the effort and cost in conducting the surveys. Over the summer of 2010, seven sample reaches of varying habitat complexity were surveyed in the Lemhi River Basin, Idaho, USA. Complete topographic surveys were attempted at each site using rtkGPS, total station, ground-based LiDaR and traditional airborne LiDaR. Separate high spatial resolution aerial imagery surveys were acquired using a tethered blimp, a drone UAV, and a traditional fixed-wing aircraft. Here we also developed a relatively simplistic methodology for deriving bathymetry from aerial imagery that could be readily employed by instream habitat monitoring programs. The quality of bathymetric maps derived from aerial imagery was compared with rtkGPS topographic data. The results are helpful for understanding the strengths and weaknesses of different approaches in specific conditions, and how a hybrid of data acquisition methods can be used to build a more complete

  18. A survey of light-scattering techniques used in the remote monitoring of atmospheric aerosols

    NASA Technical Reports Server (NTRS)

    Deirmendjian, D.

    1980-01-01

    A critical survey of the literature on the use of light-scattering mechanisms in the remote monitoring of atmospheric aerosols, their geographical and spatial distribution, and temporal variations was undertaken to aid in the choice of future operational systems, both ground based and air or space borne. An evaluation, mainly qualitative and subjective, of various techniques and systems is carried out. No single system is found to be adequate for operational purposes. A combination of earth surface and space-borne systems based mainly on passive techniques involving solar radiation with active (lidar) systems to provide auxiliary or backup information is tentatively recommended.

  19. A survey of light-scattering techniques used in the remote monitoring of atmospheric aerosols

    NASA Technical Reports Server (NTRS)

    Deirmendjian, D.

    1980-01-01

    A critical survey of the literature on the use of light-scattering mechanisms in the remote monitoring of atmospheric aerosols, their geographical and spatial distribution, and temporal variations was undertaken to aid in the choice of future operational systems, both ground based and air or space borne. An evaluation, mainly qualitative and subjective, of various techniques and systems is carried out. No single system is found to be adequate for operational purposes. A combination of earth surface and space-borne systems based mainly on passive techniques involving solar radiation with active (lidar) systems to provide auxiliary or backup information is tentatively recommended.

  20. A survey of mass analyzers. [characteristics and features of various instruments and techniques

    NASA Technical Reports Server (NTRS)

    Moore, W. W., Jr.; Tashbar, P. W.

    1973-01-01

    With the increasing applications of mass spectrometry technology to diverse services areas, a need has developed for a consolidated survey of the essential characteristics and features of the various instruments and techniques. This report is one approach to satisfying this need. Information has been collected and consolidated into a format which includes for each approach: (1) a general technique description, (2) instrument features information, and (3) a summary of pertinent advantages and disadvantages. With this information, the potential mass spectrometer user should be able to more efficiently select the most appropriate instrument.

  1. A Survey of Partition-Based Techniques for Copy-Move Forgery Detection

    PubMed Central

    Nathalie Diane, Wandji Nanda; Xingming, Sun; Moise, Fah Kue

    2014-01-01

    A copy-move forged image results from a specific type of image tampering procedure carried out by copying a part of an image and pasting it on one or more parts of the same image generally to maliciously hide unwanted objects/regions or clone an object. Therefore, detecting such forgeries mainly consists in devising ways of exposing identical or relatively similar areas in images. This survey attempts to cover existing partition-based copy-move forgery detection techniques. PMID:25152931

  2. A survey of partition-based techniques for copy-move forgery detection.

    PubMed

    Diane, Wandji Nanda Nathalie; Xingming, Sun; Moise, Fah Kue

    2014-01-01

    A copy-move forged image results from a specific type of image tampering procedure carried out by copying a part of an image and pasting it on one or more parts of the same image generally to maliciously hide unwanted objects/regions or clone an object. Therefore, detecting such forgeries mainly consists in devising ways of exposing identical or relatively similar areas in images. This survey attempts to cover existing partition-based copy-move forgery detection techniques.

  3. Nondestructive Characterization of Materials IX, AIP Conference Proceedings, No. 497 [APCPCS

    SciTech Connect

    Green, R.E., Jr.

    1999-12-01

    The papers published in these proceedings represent the latest developments in nondestructive characterization of materials. Topics covered include: acoustic emission testing; electrical techniques; laser ultrasound; magnetic techniques; multiple techniques; optical techniques; thermal techniques; ultrasonics; vibrational techniques; x-ray, neutrons, positrons, and protons.

  4. The Effects of Stress Mitigation on Nondestructive Examination

    SciTech Connect

    Dennis C. Kunerth; Eric D. Larsen; Timothy R. Mcjunkin; Arthur D. Watkins

    2004-08-01

    Ultrasonic volumetric and eddy current and visual profile surface inspections of the completed weld securing the outer lid of the Yucca Mountain waste package are required after stress mitigation. However, the technique implemented may affect the ability of the different evaluation techniques to properly characterize the completed weld. An evaluation was performed to determine the extent the nondestructive evaluation techniques are affected by two candidate mitigation processes: controlled plasticity burnishing and laser peening. This report describes the work performed and summarizes the results.

  5. Survey of Impression Materials and Techniques in Fixed Partial Dentures among the Practitioners in India

    PubMed Central

    Moldi, Arvind; Puranik, Shivakumar; Karan, Smita; Deshpande, Sumit; Neela, Neelima

    2013-01-01

    Objective. Anecdotal evidence suggests that impression materials and techniques used in general dental practice for fixed partial dentures vary from those taught in dental schools. The aim of this survey was to integrate impression techniques evolved all over the years for fixed partial dentures and to know the techniques and materials which are used in the present day by the practitioners. Materials and Methods. A total of 1000 questionnaires were sent to various practitioners in India, out of which 807 questionnaires were filled. Results. The results showed that 84.8% of prosthodontists (65.56%, urban areas) use elastomeric impression materials as well as irreversible hydrocolloids and 15.2% use irreversible hydrocolloid only. Amongst other practitioners, 55.46% use irreversible hydrocolloid (45%, rural and semiurban areas) and 44.54% use elastomeric impression materials. Elastomeric impression technique practiced most commonly is putty reline with/without spacer (77.2%); other techniques are multiple-mix and monophase techniques. Conclusion. The ideal materials, technique, and armamentarium are required for the long-term success of the treatment for fixed partial denture. Also, if the ideal procedure is not followed, it will lead to a compromised fit of the final prosthesis and failure of the treatment. PMID:23691334

  6. Survey of Impression Materials and Techniques in Fixed Partial Dentures among the Practitioners in India.

    PubMed

    Moldi, Arvind; Gala, Vimal; Puranik, Shivakumar; Karan, Smita; Deshpande, Sumit; Neela, Neelima

    2013-01-01

    Objective. Anecdotal evidence suggests that impression materials and techniques used in general dental practice for fixed partial dentures vary from those taught in dental schools. The aim of this survey was to integrate impression techniques evolved all over the years for fixed partial dentures and to know the techniques and materials which are used in the present day by the practitioners. Materials and Methods. A total of 1000 questionnaires were sent to various practitioners in India, out of which 807 questionnaires were filled. Results. The results showed that 84.8% of prosthodontists (65.56%, urban areas) use elastomeric impression materials as well as irreversible hydrocolloids and 15.2% use irreversible hydrocolloid only. Amongst other practitioners, 55.46% use irreversible hydrocolloid (45%, rural and semiurban areas) and 44.54% use elastomeric impression materials. Elastomeric impression technique practiced most commonly is putty reline with/without spacer (77.2%); other techniques are multiple-mix and monophase techniques. Conclusion. The ideal materials, technique, and armamentarium are required for the long-term success of the treatment for fixed partial denture. Also, if the ideal procedure is not followed, it will lead to a compromised fit of the final prosthesis and failure of the treatment.

  7. Effective multilevel teaching techniques on attending rounds: a pilot survey and systematic review of the literature.

    PubMed

    Certain, Laura K; Guarino, A J; Greenwald, Jeffrey L

    2011-01-01

    While numerous authors acknowledge the challenge of teaching simultaneously to medical students, interns, and residents, few offer specific advice on how to meet that challenge, and none have studied which techniques are most effective. The purpose of this study was to determine whether multilevel teaching is challenging for attendings, whether trainees feel that teaching on rounds is appropriate to their level, and to define multilevel teaching techniques. We surveyed attendings and trainees on the internal medicine services at two academic medical centers. Attendings were divided about whether teaching to multiple levels posed a challenge. Trainees reported that the teaching they received was usually appropriate to their level of training. The most effective techniques for multilevel teaching were Broadening (asking "what if" questions), Targeting (directing questions at specific team members), and Novelty (teaching newly published information), while the least effective were techniques that taught advanced material unfamiliar to most or all of the team. A systematic literature review yielded no studies that focused on multilevel teaching techniques. This article is the first to define and evaluate specific techniques for multilevel instruction in a medical setting and identifies certain techniques as more effective at engaging multiple levels of learners simultaneously.

  8. The use of guided tissue regeneration techniques among endodontists: a web-based survey.

    PubMed

    Naylor, Justin; Mines, Pete; Anderson, Alfred; Kwon, David

    2011-11-01

    The purpose of this study was to determine factors and clinical situations that influence an endodontist's decision to use guided tissue regeneration (GTR) techniques during endodontic root-end surgery. An invitation to participate in a web-based survey was e-mailed to 3,750 members of the American Association of Endodontists. Data were collected from 1,129 participants, representing a 30.1% completion rate. The number of questions varied from 3 to 11 depending on individual responses. 40.7% of respondents who perform root-end surgeries also use GTR techniques. The clinical situation in which GTR techniques are used most often is for transosseous lesions. Barrier membranes and bone replacement grafts are each used by more than 85% of respondents using GTR techniques. Insufficient training and insufficient evidence in support of its use were selected as the predominant reasons for not using GTR techniques at 42.4% and 32%, respectively. Although over 40% of respondents are currently using GTR techniques in conjunction with their root-end surgeries, a majority of those who do not use GTR indicated they would consider using these techniques with better evidence and available training. Published by Elsevier Inc.

  9. A complete denture impression technique survey of postdoctoral prosthodontic programs in the United States.

    PubMed

    Mehra, Mamta; Vahidi, Farhad; Berg, Robert W

    2014-06-01

    The purpose of the study was to survey program directors of postdoctoral prosthodontic programs in the United States regarding their programs' complete denture impression techniques. The key objectives of the survey were to identify the current trends in complete denture impression making and to determine which techniques and materials are taught in US postdoctoral prosthodontic programs. An online survey was sent to all program directors of US postdoctoral prosthodontic programs. The survey comprised two sections: preliminary impressions and final impressions. The survey contained 22 questions that would take approximately 5 minutes to complete. All responses remained anonymous throughout the survey. The response rate for the survey was 87%. A majority of the programs did not separately border mold the tray prior to making the preliminary impressions (82%). The impression material of choice for the preliminary impression was irreversible hydrocolloid (88%). Selective pressure was the predominantly used impression philosophy (80%). All programs border molded the custom tray, and 95% recorded the borders in sections. The material of choice for border molding the custom tray was modeling plastic impression compound (71%). The most commonly used impression material for the final impressions was polyvinylsiloxane (PVS) (42%), and the second most commonly used impression material was polysulphide (32%). The most common technique for locating the posterior palatal seal was marking intraorally and transferring onto the final impression (65%). Most programs routinely advised their patients not to wear their existing dentures for at least 24 hours before the final impressions were made (83%). Based on the results of this study, the following conclusions can be drawn: (1) The most commonly used material for the preliminary impression was irreversible hydrocolloid and for the final impression was PVS. (2) Modeling plastic impression compound was used by most programs to

  10. Radioactive nondestructive test method

    NASA Technical Reports Server (NTRS)

    Obrien, J. R.; Pullen, K. E.

    1971-01-01

    Various radioisotope techniques were used as diagnostic tools for determining the performance of spacecraft propulsion feed system elements. Applications were studied in four tasks. The first two required experimental testing involving the propellant liquid oxygen difluoride (OF2): the neutron activation analysis of dissolved or suspended metals, and the use of radioactive tracers to evaluate the probability of constrictions in passive components (orifices and filters) becoming clogged by matter dissolved or suspended in the OF2. The other tasks were an appraisal of the applicability of radioisotope techniques to problems arising from the exposure of components to liquid/gas combinations, and an assessment of the applicability of the techniques to other propellants.

  11. Evaluation of methods for nondestructive testing of brazed joints

    NASA Technical Reports Server (NTRS)

    Kanno, A.

    1968-01-01

    Evaluation of nondestructive methods of testing brazed joints reveals that ultrasonic testing is effective in the detection of nonbonds in diffusion bonded samples. Radiography provides excellent resolutions of void or inclusion defects, and the neutron radiographic technique shows particular advantage for brazing materials containing cadmium.

  12. Thermal nondestructive examination method for thermal-spray coatings

    SciTech Connect

    Green, D.R.; Schmeller, M.D.; Sulit, R.A.

    1983-05-01

    This paper describes a feasibility demonstration of a thermal scanning NDE (nondestructive examination) system for thermal-spray coatings. Non-bonds were detected between several types of coatings and their substrates. Aluminum anti-skid coatings having very rough surfaces were included. A technique for producing known non-bond areas for calibrating and demonstrating NDE methods was developed.

  13. Research on Advanced Nondestructive Evaluation (NDE) Methods for Aerospace Structures

    DTIC Science & Technology

    2004-03-01

    Technique ...............................................................15 3.2.4 Three-Element Transducer for High -Precision RSW-Velocity...shown to have a very high potential for nondestructively monitoring metalworking processes. 3 Section 2 Introduction This program was...characterizing properties of coatings, thin films, and materials undergoing high cycle fatigue, and for detecting and characterizing corrosion. • Identify and

  14. Nondestructive evaluation of oriented strand board exposed to decay fungi.

    Treesearch

    Barbara L. Illman; Vina W. Yang; Robert J. Ross; William J. Nelson

    2002-01-01

    Stress wave nondestructive evaluation (NDE) technologies are being used in our laboratory to evaluate the performance properties of engineered wood. These techniques have proven useful in the inspection of timber structures to locate internal voids and decayed or deteriorated areas in large timbers. But no information exists concerning NDE and important properties of...

  15. Nondestructive Methods for Detecting Defects in Softwood Logs

    Treesearch

    Kristin C. Schad; Daniel L. Schmoldt; Robert J. Ross

    1996-01-01

    Wood degradation and defects, such as voids and knots, affect the quality and processing time of lumber. The ability to detect internal defects in the log can save mills time and processing costs. In this study, we investigated three nondestructive evaluation techniques for detecting internal wood defects. Sound wave transmission, x-ray computed tomography, and impulse...

  16. Stress wave nondestructive evaluation of Douglas-fir peeler cores

    Treesearch

    Robert J. Ross; John I. Zerbe; Xiping Wang; David W. Green; Roy F. Pellerin

    2005-01-01

    With the need for evaluating the utilization of veneer peeler log cores in higher value products and the increasing importance of utilizing round timbers in poles, posts, stakes, and building construction components, we conducted a cooperative project to verify the suitability of stress wave nondestructive evaluation techniques for assessing peeler cores and some...

  17. Nondestructive testing for assessing wood members in structures : a review

    Treesearch

    R. J. Ross; R. F. Pellerin

    1994-01-01

    Numerous organizations have conducted research to develop nondestructive testing (NDT) techniques for assessing the condition of wood members in structures. A review of this research was published in 1991. This is an update of the 1991 report. It presents a comprehensive review of published research on the development and use of NDT tools for in-place assessment of...

  18. A survey of simulation and diagnostic techniques for hypersonic nonequilibrium flows

    NASA Technical Reports Server (NTRS)

    Sharma, Surendra P.; Park, Chul

    1987-01-01

    The possible means of simulating nonequilibrium reacting flows in hypersonic environments, and the required diagnostic techniques, are surveyed in two categories: bulk flow behavior and determination of chemical rate parameters. Flow visualization of shock shapes for validation of computational-fluid dynamic calculations is proposed. The facilities and the operating conditions necessary to produce the required nonequilibrium conditions, the suitable optical techniques, and their sensitivity requirements, are surveyed. Shock-tubes, shock-tunnels, and ballistic ranges in a wide range of sizes and strengths are found to be useful for this purpose, but severe sensitivity requirements are indicated for the optical instruments, which can be met only by using highly-collimated laser sources. Likewise, for the determination of chemical parameters, this paper summarizes the quantities that need to be determined, required facilities and their operating conditions, and the suitable diagnostic techniques and their performance requirements. Shock tubes of various strengths are found to be useful for this purpose. Vacuum ultraviolet absorption and fluorescence spectroscopy and coherent anti-Stokes Raman spectroscopy are found to be the techniques best suited for the measurements of the chemical data.

  19. Nondestructive detection of polar molecules via Rydberg atoms

    NASA Astrophysics Data System (ADS)

    Zeppenfeld, M.

    2017-04-01

    A highly sensitive, general, and preferably nondestructive technique to detect polar molecules would greatly advance a number of fields, in particular quantum science with cold and ultracold molecules. Here, we propose using resonant energy transfer between molecules and Rydberg atoms to detect molecules. Based on an energy transfer cross-section of > 10-6 cm2 for sufficiently low collision energies, a near unit efficiency non-destructive detection of basically any polar molecule species in a well-defined internal state should be possible.

  20. Nondestructive Evaluation of Wood: Second Edition

    Treesearch

    Robert J. Ross

    2015-01-01

    This report summarizes information on nondestructive testing and evaluation of wood. It includes information on a wide range of nondestructive assessment technologies and their uses for evaluating various wood products.

  1. Quantitative Ultrasound for Nondestructive Characterization of Engineered Tissues and Biomaterials.

    PubMed

    Dalecki, Diane; Mercado, Karla P; Hocking, Denise C

    2016-03-01

    Non-invasive, non-destructive technologies for imaging and quantitatively monitoring the development of artificial tissues are critical for the advancement of tissue engineering. Current standard techniques for evaluating engineered tissues, including histology, biochemical assays and mechanical testing, are destructive approaches. Ultrasound is emerging as a valuable tool for imaging and quantitatively monitoring the properties of engineered tissues and biomaterials longitudinally during fabrication and post-implantation. Ultrasound techniques are rapid, non-invasive, non-destructive and can be easily integrated into sterile environments necessary for tissue engineering. Furthermore, high-frequency quantitative ultrasound techniques can enable volumetric characterization of the structural, biological, and mechanical properties of engineered tissues during fabrication and post-implantation. This review provides an overview of ultrasound imaging, quantitative ultrasound techniques, and elastography, with representative examples of applications of these ultrasound-based techniques to the field of tissue engineering.

  2. Quantitative Ultrasound for Nondestructive Characterization of Engineered Tissues and Biomaterials

    PubMed Central

    Dalecki, Diane; Mercado, Karla P.; Hocking, Denise C.

    2015-01-01

    Non-invasive, non-destructive technologies for imaging and quantitatively monitoring the development of artificial tissues are critical for the advancement of tissue engineering. Current standard techniques for evaluating engineered tissues, including histology, biochemical assays and mechanical testing, are destructive approaches. Ultrasound is emerging as a valuable tool for imaging and quantitatively monitoring the properties of engineered tissues and biomaterials longitudinally during fabrication and post-implantation. Ultrasound techniques are rapid, non-invasive, non-destructive and can be easily integrated into sterile environments necessary for tissue engineering. Furthermore, high-frequency quantitative ultrasound techniques can enable volumetric characterization of the structural, biological, and mechanical properties of engineered tissues during fabrication and post-implantation. This review provides an overview of ultrasound imaging, quantitative ultrasound techniques, and elastography, with representative examples of applications of these ultrasound-based techniques to the field of tissue engineering. PMID:26581347

  3. Nondestructive characterization of low-level transuranic waste

    SciTech Connect

    Barna, B.A.; Reinhardt, W.W.

    1981-10-01

    The use of nondestructive evaluation (NDE) methods is proposed for characterization of transuranic (TRU) waste stored at the Radioactive Waste Management Complex. These NDE methods include real-time x-ray radiography, real-time neutron radiography, x-ray and neutron computed tomography, thermal imaging, container weighing, visual examination, and acoustic measurements. An integrated NDE system is proposed for characterization and certification of TRU waste destined for eventual shipment to the Waste Isolation Pilot Plant in New Mexico. Methods for automating both the classification waste and control of a complete nondestructive evaluation/nondestructive assay system are presented. Feasibility testing of the different NDE methods, including real-time x-ray radiography, and development of automated waste classification techniques are covered as part of a five year effort designed to yield a production waste characterization system.

  4. Nondestructive verification and assay systems for spent fuels

    SciTech Connect

    Cobb, D.D.; Phillips, J.R.; Bosler, G.E.; Eccleston, G.W.; Halbig, J.K.; Hatcher, C.R.; Hsue, S.T.

    1982-04-01

    This is an interim report of a study concerning the potential application of nondestructive measurements on irradiated light-water-reactor (LWR) fuels at spent-fuel storage facilities. It describes nondestructive measurement techniques and instruments that can provide useful data for more effective in-plant nuclear materials management, better safeguards and criticality safety, and more efficient storage of spent LWR fuel. In particular, several nondestructive measurement devices are already available so that utilities can implement new fuel-management and storage technologies for better use of existing spent-fuel storage capacity. The design of an engineered prototype in-plant spent-fuel measurement system is approx. 80% complete. This system would support improved spent-fuel storage and also efficient fissile recovery if spent-fuel reprocessing becomes a reality.

  5. On-line nondestructive methods for examining fuel particles

    SciTech Connect

    Pardini, A.F.; Bond, L.J.; Good, M.S.; Bunch, K.J.; Sandness, G.A.; Hockey, R.L.; Saurwein, J.J.; Gray, J.N.

    2007-07-01

    Tri-isotropic (TRISO) particle fuels are being considered for use in various advanced nuclear power reactors and about 15 billion of these small ({approx} 1 mm diameter) spheres are needed for a single fuel load. Current quality control methods are manual, often destructive of test specimens, and they are economically impractical for automated application at commercial scale. Replacing these methods with new nondestructive evaluation techniques, automated for higher speed, will make fuel production and reactor operation economically more attractive. This paper reports aspects of a project to develop and demonstrate nondestructive examination methods to detect and reject defective particles. The work explored adapting, developing, and demonstrating innovative nondestructive test methods to cost-effectively assure the quality of large percentages of the fuel particles. (authors)

  6. On-Line Nondestructive Methods for Examining Fuel Particles

    SciTech Connect

    Pardini, Allan F.; Bond, Leonard J.; Good, Morris S.; Bunch, Kyle J.; Sandness, Gerald A.; Hockey, Ronald L.; Saurwein, John J.; Gray, Joseph N.

    2007-09-15

    Tri-isotropic (TRISO) particle fuels, being considered for use in various advanced nuclear power reactors, consist of sub-millimeter diameter uranium oxide spheres uniformly coated to prevent the release of fission products into the reactor. About 15 billion of these spheres are needed to fuel a single reactor. Current quality control (QC) methods are manual, can destroy test specimens, and are not economically feasible. Replacing these methods with nondestructive evaluation (NDE) techniques, automated for higher speed, will make fuel production and reactor operation economically feasible, considering the requirement for extremely large fuel particle throughput rates. This paper reports a project to develop and demonstrate nondestructive examination methods to detect and reject defective particles, and in particular progress made in the final year of a Nuclear Energy Research Initiative (NERI) project . The work explored adapting, developing, and demonstrating innovative nondestructive test methods to cost-effectively assure the quality of large percentages of the fuel particles.

  7. A comparison of conventional and grid techniques for chest radiography in field surveys

    PubMed Central

    Washington, J. S.; Dick, J. A.; Jacobsen, M.; Prentice, W. M.

    1973-01-01

    Washington, J. S., Dick, J. A., Jacobsen, M., and Prentice, W. M. (1973).British Journal of Industrial Medicine,30, 365-374. A comparison of conventional and grid techniques for chest radiography in field surveys. The effect on the quality of chest radiographs using a reciprocating grid with a moderately high kilovoltage (96 to 105 kV) has been studied. A total of 1 710 mineworkers had two postero-anterior chest radiographs taken at the same visit to a linked pair of mobile ϰ-ray units. One film was taken with conventional exposure factors and the other with moderately high kilovoltage and a reciprocating grid. The grid was exchanged between the two units according to a randomized plan so that the first radiograph was not always taken with the same technique. The 3 420 films so produced were subsequently assessed for quality by five doctors experienced in reading chest films. The films were examined singly in random order and the reader did not know which technique had been used for a given film. Four of the readers recorded improved quality using the grid technique for films from men whose antero-posterior chest measurements exceeded 254 mm (10 in), but they preferred the conventional exposure technique for films from men whose chest measurements were less than 254 mm. Results from all film pairs where a difference in quality was recorded showed no overall advantage for either technique. PMID:4753720

  8. TESTING GROUND BASED GEOPHYSICAL TECHNIQUES TO REFINE ELECTROMAGNETIC SURVEYS NORTH OF THE 300 AREA HANFORD WASHINGTON

    SciTech Connect

    PETERSEN SW

    2010-12-02

    Airborne electromagnetic (AEM) surveys were flown during fiscal year (FY) 2008 within the 600 Area in an attempt to characterize the underlying subsurface and to aid in the closure and remediation design study goals for the 200-PO-1 Groundwater Operable Unit (OU). The rationale for using the AEM surveys was that airborne surveys can cover large areas rapidly at relatively low costs with minimal cultural impact, and observed geo-electrical anomalies could be correlated with important subsurface geologic and hydrogeologic features. Initial interpretation of the AEM surveys indicated a tenuous correlation with the underlying geology, from which several anomalous zones likely associated with channels/erosional features incised into the Ringold units were identified near the River Corridor. Preliminary modeling resulted in a slightly improved correlation but revealed that more information was required to constrain the modeling (SGW-39674, Airborne Electromagnetic Survey Report, 200-PO-1 Groundwater Operable Unit, 600 Area, Hanford Site). Both time-and frequency domain AEM surveys were collected with the densest coverage occurring adjacent to the Columbia River Corridor. Time domain surveys targeted deeper subsurface features (e.g., top-of-basalt) and were acquired using the HeliGEOTEM{reg_sign} system along north-south flight lines with a nominal 400 m (1,312 ft) spacing. The frequency domain RESOLVE system acquired electromagnetic (EM) data along tighter spaced (100 m [328 ft] and 200 m [656 ft]) north-south profiles in the eastern fifth of the 200-PO-1 Groundwater OU (immediately adjacent to the River Corridor). The overall goal of this study is to provide further quantification of the AEM survey results, using ground based geophysical methods, and to link results to the underlying geology and/or hydrogeology. Specific goals of this project are as follows: (1) Test ground based geophysical techniques for the efficacy in delineating underlying geology; (2) Use ground

  9. NONDESTRUCTIVE EVALUATION OF CERAMIC CANDLE FILTERS

    SciTech Connect

    Roger H.L. Chen, Ph.D.; Alejandro Kiriakidis

    1999-09-01

    Nondestructive evaluation (NDE) techniques have been used to reduce the potential mechanical failures and to improve the reliability of a structure. Failure of a structure is usually initiated at some type of flaw in the material. NDE techniques have been developed to determine the presence of flaws larger than an acceptable size and to estimate the remaining stiffness of a damaged structure (Chen, et. al, 1995). Ceramic candle filters have been tested for use in coal-fueled gas turbine systems. They protect gas turbine components from damage due to erosion. A total of one hundred and one candle filters were nondestructively evaluated in this study. Ninety-eight ceramic candle filters and three ceramic composite filters have been nondestructively inspected using dynamic characterization technique. These ceramic filters include twelve unused Coors alumina/mullite, twenty-four unused and fifteen used Schumacher-Dia-Schumalith TF-20, twenty-five unused and nine used Refractron 326, eight unused and three used Refractron 442T, one new Schumacher-T 10-20, and one used Schumacher-Dia-Schumalith F-40. All filters were subjected to a small excitation and the dynamic response was picked up by a piezoelectric accelerometer. The evaluation of experimental results was processed using digital signal analysis technique including various forms of data transformation. The modal parameters for damage assessment for the unexposed (unused) vs. exposed (used) specimen were based on two vibration parameters: natural frequencies and mode shapes. Finite Element models were built for each specimen type to understand its dynamic response. Linear elastic modal analysis was performed using eight nodes, three-dimensional isotropic solid elements. Conclusions based on our study indicate that dynamic characterization is a feasible NDE technique in studying structural properties of ceramic candle filters. It has been shown that the degradation of the filters due to long working hours (or

  10. Non-destructive measurement of soil liquefaction density change by crosshole radar tomography, Treasure Island, California

    USGS Publications Warehouse

    Kayen, Robert E.; Barnhardt, Walter A.; Ashford, Scott; Rollins, Kyle

    2000-01-01

    A ground penetrating radar (GPR) experiment at the Treasure Island Test Site [TILT] was performed to non-destructively image the soil column for changes in density prior to, and following, a liquefaction event. The intervening liquefaction was achieved by controlled blasting. A geotechnical borehole radar technique was used to acquire high-resolution 2-D radar velocity data. This method of non-destructive site characterization uses radar trans-illumination surveys through the soil column and tomographic data manipulation techniques to construct radar velocity tomograms, from which averaged void ratios can be derived at 0.25 - 0.5m pixel footprints. Tomograms of void ratio were constructed through the relation between soil porosity and dielectric constant. Both pre- and post-blast tomograms were collected and indicate that liquefaction related densification occurred at the site. Volumetric strains estimated from the tomograms correlate well with the observed settlement at the site. The 2-D imagery of void ratio can serve as high-resolution data layers for numerical site response analysis.

  11. Atlantis Non-destructive Testing

    NASA Image and Video Library

    2003-10-29

    In the Orbiter Processing Facility, the nose cap (foreground) removed from Atlantis (behind) waits to be shipped to the original manufacturing company, Vought in Ft. Worth, Texas, a subsidiary of Lockheed Martin, to undergo non-destructive testing such as CAT scan and thermography.

  12. The Randomized Response Technique Application in the Survey of Homosexual Commercial Sex among Men in Beijing

    PubMed Central

    CHEN, Xiangyu; DU, Qiaoqiao; JIN, Zongda; XU, Tian; SHI, Jiachen; GAO, Ge

    2014-01-01

    Abstract Background Traditional survey methods may cause refusals to respond or untruthful replies when encounter the sensitive questions. The Randomized Response Technique (RRT) is designed to decrease social desirability bias and obtain reliable estimates. This study aimed to apply these new methods on the sensitive questions survey. Methods Simmons model was applied in the survey of issues relevant to commercial sex among men who have sex with men (MSM) in Beijing, China. Stratified two-stage sampling and stratified random sampling were applied. Results During July to December 2010 in Beijing, the commercial sex proportion among MSM was 0.051(95% CI: 0.017, 0.085), its estimated variance was 3.01×10-4. The last male condom use rate during commercial sex was 0.778(95% CI: 0.746, 0.810), its estimated variance was 2.6×10-4. Conclusion We have introduced new approaches for the sensitive question survey among MSM. The new approaches are proved to be reliable and valid. PMID:26005651

  13. Chest physiotherapy techniques in neurological intensive care units of India: A survey

    PubMed Central

    Bhat, Anup; Chakravarthy, Kalyana; Rao, Bhamini K.

    2014-01-01

    Context: Neurological intensive care units (ICUs) are a rapidly developing sub-specialty of neurosciences. Chest physiotherapy techniques are of great value in neurological ICUs in preventing, halting, or reversing the impairments caused due to neurological disorder and ICU stay. However, chest physiotherapy techniques should be modified to a greater extent in the neurological ICU as compared with general ICUs. Aim: The aim of this study is to obtain data on current chest physiotherapy practices in neurological ICUs of India. Settings and Design: A tertiary care hospital in Karnataka, India, and cross-sectional survey. Subjects and Methods: A questionnaire was formulated and content validated to assess the current chest physiotherapy practices in neurological ICUs of India. The questionnaire was constructed online and a link was distributed via E-mail to 185 physiotherapists working in neurological ICUs across India. Statistical Analysis Used: Descriptive statistics. Results: The response rate was 44.3% (n = 82); 31% of the physiotherapists were specialized in cardiorespiratory physiotherapy and 30% were specialized in neurological physiotherapy. Clapping, vibration, postural drainage, aerosol therapy, humidification, and suctioning were used commonly used airway clearance (AC) techniques by the majority of physiotherapists. However, devices for AC techniques such as Flutter, Acapella, and standard positive expiratory pressure devices were used less frequently for AC. Techniques such as autogenic drainage and active cycle of breathing technique are also frequently used when appropriate for the patients. Lung expansion therapy techniques such as breathing exercises, incentive spirometry exercises, and positioning, proprioceptive neuromuscular facilitation of breathing are used by majority of physiotherapists. Conclusions: Physiotherapists in this study were using conventional chest physiotherapy techniques more frequently in comparison to the devices available for

  14. Chest physiotherapy techniques in neurological intensive care units of India: A survey.

    PubMed

    Bhat, Anup; Chakravarthy, Kalyana; Rao, Bhamini K

    2014-06-01

    Neurological intensive care units (ICUs) are a rapidly developing sub-specialty of neurosciences. Chest physiotherapy techniques are of great value in neurological ICUs in preventing, halting, or reversing the impairments caused due to neurological disorder and ICU stay. However, chest physiotherapy techniques should be modified to a greater extent in the neurological ICU as compared with general ICUs. The aim of this study is to obtain data on current chest physiotherapy practices in neurological ICUs of India. A tertiary care hospital in Karnataka, India, and cross-sectional survey. A questionnaire was formulated and content validated to assess the current chest physiotherapy practices in neurological ICUs of India. The questionnaire was constructed online and a link was distributed via E-mail to 185 physiotherapists working in neurological ICUs across India. Descriptive statistics. The response rate was 44.3% (n = 82); 31% of the physiotherapists were specialized in cardiorespiratory physiotherapy and 30% were specialized in neurological physiotherapy. Clapping, vibration, postural drainage, aerosol therapy, humidification, and suctioning were used commonly used airway clearance (AC) techniques by the majority of physiotherapists. However, devices for AC techniques such as Flutter, Acapella, and standard positive expiratory pressure devices were used less frequently for AC. Techniques such as autogenic drainage and active cycle of breathing technique are also frequently used when appropriate for the patients. Lung expansion therapy techniques such as breathing exercises, incentive spirometry exercises, and positioning, proprioceptive neuromuscular facilitation of breathing are used by majority of physiotherapists. Physiotherapists in this study were using conventional chest physiotherapy techniques more frequently in comparison to the devices available for AC.

  15. Nurse Practitioners' Use of Communication Techniques: Results of a Maryland Oral Health Literacy Survey.

    PubMed

    Koo, Laura W; Horowitz, Alice M; Radice, Sarah D; Wang, Min Q; Kleinman, Dushanka V

    2016-01-01

    We examined nurse practitioners' use and opinions of recommended communication techniques for the promotion of oral health as part of a Maryland state-wide oral health literacy assessment. Use of recommended health-literate and patient-centered communication techniques have demonstrated improved health outcomes. A 27-item self-report survey, containing 17 communication technique items, across 5 domains, was mailed to 1,410 licensed nurse practitioners (NPs) in Maryland in 2010. Use of communication techniques and opinions about their effectiveness were analyzed using descriptive statistics. General linear models explored provider and practice characteristics to predict differences in the total number and the mean number of communication techniques routinely used in a week. More than 80% of NPs (N = 194) routinely used 3 of the 7 basic communication techniques: simple language, limiting teaching to 2-3 concepts, and speaking slowly. More than 75% of respondents believed that 6 of the 7 basic communication techniques are effective. Sociodemographic provider characteristics and practice characteristics were not significant predictors of the mean number or the total number of communication techniques routinely used by NPs in a week. Potential predictors for using more of the 7 basic communication techniques, demonstrating significance in one general linear model each, were: assessing the office for user-friendliness and ever taking a communication course in addition to nursing school. NPs in Maryland self-reported routinely using some recommended health-literate communication techniques, with belief in their effectiveness. Our findings suggest that NPs who had assessed the office for patient-friendliness or who had taken a communication course beyond their initial education may be predictors for using more of the 7 basic communication techniques. These self-reported findings should be validated with observational studies. Graduate and continuing education for NPs

  16. Nurse Practitioners' Use of Communication Techniques: Results of a Maryland Oral Health Literacy Survey

    PubMed Central

    Koo, Laura W.; Horowitz, Alice M.; Radice, Sarah D.; Wang, Min Q.; Kleinman, Dushanka V.

    2016-01-01

    Objectives We examined nurse practitioners’ use and opinions of recommended communication techniques for the promotion of oral health as part of a Maryland state-wide oral health literacy assessment. Use of recommended health-literate and patient-centered communication techniques have demonstrated improved health outcomes. Methods A 27-item self-report survey, containing 17 communication technique items, across 5 domains, was mailed to 1,410 licensed nurse practitioners (NPs) in Maryland in 2010. Use of communication techniques and opinions about their effectiveness were analyzed using descriptive statistics. General linear models explored provider and practice characteristics to predict differences in the total number and the mean number of communication techniques routinely used in a week. Results More than 80% of NPs (N = 194) routinely used 3 of the 7 basic communication techniques: simple language, limiting teaching to 2–3 concepts, and speaking slowly. More than 75% of respondents believed that 6 of the 7 basic communication techniques are effective. Sociodemographic provider characteristics and practice characteristics were not significant predictors of the mean number or the total number of communication techniques routinely used by NPs in a week. Potential predictors for using more of the 7 basic communication techniques, demonstrating significance in one general linear model each, were: assessing the office for user-friendliness and ever taking a communication course in addition to nursing school. Conclusions NPs in Maryland self-reported routinely using some recommended health-literate communication techniques, with belief in their effectiveness. Our findings suggest that NPs who had assessed the office for patient-friendliness or who had taken a communication course beyond their initial education may be predictors for using more of the 7 basic communication techniques. These self-reported findings should be validated with observational studies

  17. [Abortion in Brazil: a household survey using the ballot box technique].

    PubMed

    Diniz, Debora; Medeiros, Marcelo

    2010-06-01

    This study presents the first results of the National Abortion Survey (PNA, Pesquisa Nacional de Aborto), a household random sample survey fielded in 2010 covering urban women in Brazil aged 18 to 39 years. The PNA combined two techniques, interviewer-administered questionnaires and self-administered ballot box questionnaires. The results of PNA show that at the end of their reproductive health one in five women has performed an abortion, with abortions being more frequent in the main reproductive ages, that is, from 18 to 29 years old. No relevant differentiation was observed in the practice of abortion among religious groups, but abortion was found to be more common among people with lower education. The use of medical drugs to induce abortion occurred in half of the abortions, and post-abortion hospitalization was observed among approximately half of the women who aborted. Such results lead to conclude that abortion is a priority in the Brazilian public health agenda.

  18. Nondestructive testing of waste drum integrity

    SciTech Connect

    Jackson, C.N. Jr.

    1983-01-01

    Nondestructive techniques have been investigated to evaluate the structural integrity of low-level transuranic waste drums that have been buried in the ground for up to 15 years. Measurements of artificially corroded samples evaluated suitability, accuracy and rapidity with which commercially available instruments and transducers could perform the examination. Several available instruments have thickness measuring capability and probably could be tailored with a relatively minor amount of effort for precise measurement of the relatively thin wall thickness of a drum or bin. The ultrasonic method was shown capable of providing precise measurement of wall thickness for most critical areas of a drum. Some data were lost due to dents, rust, seams and labels. However, this work characterized the capability of the technique, and it can now be assessed against the need as repository requirements are more completely identified.

  19. Nondestructive testing of Scout rocket motors

    NASA Technical Reports Server (NTRS)

    Oaks, A. E.

    1972-01-01

    The nondestructive tests applied to Scout rocket motors were reviewed and appraised. Analytical techniques were developed to evaluate the capabilities of the radiographic and ultrasonic procedures used. Major problem areas found were the inadequacy of high voltage radiography for detecting unbonds and propellant cracks having narrow widths, the inability to relate the ultrasonic signals received from flat-bottomed holes in standards to those received from real defects and in the general area of the specification of acceptance criteria and how these were to be met. To counter the deficiencies noted, analyses were conducted to the potential utility of radiometric, acoustic, holographic and thermographic techniques for motor and nozzle bond inspection, a new approach to qualifying magnetic particle inspection and the application of acoustic emission analysis to the evaluation of proof and leak test data.

  20. Nondestructive Evaluation and Monitoring Results from COPV Accelerated Stress Rupture Testing

    NASA Astrophysics Data System (ADS)

    Saulsberry, Regor L.; Greene, Nathanael J.; Banks, Curtis E.; Madaras, Eric I.; Waller, Jess M.; Forth, Scott C.; Russell, Rick W.

    2010-09-01

    To project objective is to develop and demonstrate nondestructive evaluation(NDE) techniques capable of assessing stress rupture related strength degradation for carbon composite pressure vessels, either in a structural health monitoring(SHM) or periodic inspection mode.

  1. Speckle reference beam holographic and speckle photographic interferometry in non-destructive test systems

    NASA Technical Reports Server (NTRS)

    Liu, H. K.

    1976-01-01

    The techniques of speckle beam holographic interferometry and speckle photographic interferometry are described. In particular, their practical limitations and their applications to the existing holographic nondestructive test system are discussed.

  2. Survey of radiographic requirements and techniques in United States dental assisting programs, 1982

    SciTech Connect

    Farman, A.G.; Grammer, S.; Hunter, N.; Baker, C.

    1983-10-01

    A survey of dental assisting programs revealed little standardization of student requirements for dental radiography in the United States. Areas for concern were: the high proportion of programs in which classmates exposed one another to ionizing radiation for training purposes; and the continued use of closed cones in some cases. Preclinical laboratories in radiography were, on average, of considerably longer duration than those previously reported for dental students. Conversely, clinical requirements in intraoral techniques were less for dental assisting students than is the case for dental students. Available methods of reducing patient exposure to ionizing radiation are not being fully implemented.

  3. A Review of Microwave Thermography Nondestructive Testing and Evaluation

    PubMed Central

    Zhang, Hong; Yang, Ruizhen; He, Yunze; Foudazi, Ali; Cheng, Liang; Tian, Guiyun

    2017-01-01

    Microwave thermography (MWT) has many advantages including strong penetrability, selective heating, volumetric heating, significant energy savings, uniform heating, and good thermal efficiency. MWT has received growing interest due to its potential to overcome some of the limitations of microwave nondestructive testing (NDT) and thermal NDT. Moreover, during the last few decades MWT has attracted growing interest in materials assessment. In this paper, a comprehensive review of MWT techniques for materials evaluation is conducted based on a detailed literature survey. First, the basic principles of MWT are described. Different types of MWT, including microwave pulsed thermography, microwave step thermography, microwave pulsed phase thermography, and microwave lock-in thermography are defined and introduced. Then, MWT case studies are discussed. Next, comparisons with other thermography and NDT methods are conducted. Finally, the trends in MWT research are outlined, including new theoretical studies, simulations and modelling, signal processing algorithms, internal properties characterization, automatic separation and inspection systems. This work provides a summary of MWT, which can be utilized for material failures prevention and quality control. PMID:28505130

  4. A Review of Microwave Thermography Nondestructive Testing and Evaluation.

    PubMed

    Zhang, Hong; Yang, Ruizhen; He, Yunze; Foudazi, Ali; Cheng, Liang; Tian, Guiyun

    2017-05-15

    Microwave thermography (MWT) has many advantages including strong penetrability, selective heating, volumetric heating, significant energy savings, uniform heating, and good thermal efficiency. MWT has received growing interest due to its potential to overcome some of the limitations of microwave nondestructive testing (NDT) and thermal NDT. Moreover, during the last few decades MWT has attracted growing interest in materials assessment. In this paper, a comprehensive review of MWT techniques for materials evaluation is conducted based on a detailed literature survey. First, the basic principles of MWT are described. Different types of MWT, including microwave pulsed thermography, microwave step thermography, microwave pulsed phase thermography, and microwave lock-in thermography are defined and introduced. Then, MWT case studies are discussed. Next, comparisons with other thermography and NDT methods are conducted. Finally, the trends in MWT research are outlined, including new theoretical studies, simulations and modelling, signal processing algorithms, internal properties characterization, automatic separation and inspection systems. This work provides a summary of MWT, which can be utilized for material failures prevention and quality control.

  5. Nondestructive evaluation of thick concrete structures

    NASA Astrophysics Data System (ADS)

    Clayton, Dwight A.

    2015-03-01

    Concrete has been used in the construction of nuclear power plants (NPPs) due to three primary properties: its low cost, structural strength, and ability to shield radiation. Examples of concrete structures important to the safety of Light Water Reactor (LWR) plants include the containment building, spent fuel pool, and cooling towers. Use in these structures has made concrete's long-term performance crucial for the safe operation of commercial NPPs. Extending LWR operating period to 60 years and beyond will likely increase susceptibility and severity of known forms of degradation. New mechanisms of materials degradation are also possible. This creates the need to be able to nondestructively evaluate the current subsurface concrete condition of aging concrete material in NPP structures. The size and complexity of NPP containment structures and heterogeneity of Portland cement concrete make characterization of the degradation extent a difficult task. Specially designed and fabricated test specimens can provide realistic flaws that are similar to actual flaws in terms of how they interact with a particular nondestructive evaluation (NDE) technique. Artificial test blocks allow the isolation of certain testing problems as well as the variation of certain parameters. Representative large heavily reinforced concrete specimens would allow for comparative testing to evaluate the state-of-the-art NDE in this area and to identify additional developments necessary to address the challenges potentially found in NPPs.

  6. Use of robotics in nondestructive inspection

    SciTech Connect

    Sartell, R.J.; Richards, W.J.

    1987-01-01

    Until very recently, nondestructive inspection of aircraft components at McClellan Air Force Base had been done in the traditional way. Ultrasonic inspections have been performed using hand-held equipment. X-ray inspections were performed using film radiography with the x-ray tubes being held on cradles, tripods, or suspended from pendant-operated or manual overhead crane-type fixtures. Implementation of advanced ultrasonic and real-time x-ray systems required that new equipment handling and parts handling methods be devised. Aircraft flight safety considerations demanded that neutron radiography be implemented as an inspection technique in order to find low levels of moisture and corrosion in the F-111 aircraft structure and aerodynamic surfaces. Traditional nondestructive inspection (NDI) methods require removal of suspect panels from the aircraft, including some panels that were not designed to be removed. The solution to these problems was to implement NDI systems that would allow inspection of intact aircraft. A new NDI facility especially designed for the latest in technology is under construction. It will house two large maneuverable x- and n-ray systems. The approx. 90-ft-span gantry robots will scan intact aircraft with real-time x-ray and near real-time n-ray systems. A unique floor/rail-mounted n-ray system will automatically inspect the F-111 aircraft engine bays.

  7. Complementary Electromagnetic Non-Destructive Evaluation

    NASA Astrophysics Data System (ADS)

    Tian, Gui Yun; Wilson, John; Morozov, Maxim

    2011-06-01

    The use of non-destructive evaluation (NDE) for defect detection and failure prediction in structures and specimens is widespread in energy industries, aimed at ageing power plants and pipelines, material degradation, fatigue and radiation damage, etc. At present there are no suitable electromagnetic NDE methods for the measurement and characterization of material degradation, in irradiated samples in particular, which is very important and timely for the nuclear power industry in the UK. This paper reports recent developments in the field of electromagnetic (EM) NDE at Newcastle University, including pulsed eddy current (PEC), pulsed magnetic flux leakage (PMFL), magnetic Barkhausen emission (MBE) and magneto-acoustic emission (MAE). As different EM methods have different strengths, an integrative EM framework is introduced. Case studies through the second round robin tests organized by the Universal Network for Magnetic Non-Destructive Evaluation (UNMNDE), representing eighteen leading research groups worldwide in the area of electromagnetic NDE, are reported. Twelve samples with different ageing times and rolling reduction ratios were tested using different magnetic methods among the UNMNDE members. Based on the studies, the complementary characteristics of electromagnetic techniques for NDE are discussed.

  8. Techniques used for the isolation and characterization of extracellular vesicles: results of a worldwide survey

    PubMed Central

    Gardiner, Chris; Vizio, Dolores Di; Sahoo, Susmita; Théry, Clotilde; Witwer, Kenneth W.; Wauben, Marca; Hill, Andrew F.

    2016-01-01

    Extracellular vesicles (EVs) represent an important mode of intercellular communication. Research in this field has grown rapidly in the last few years, and there is a plethora of techniques for the isolation and characterization of EVs, many of which are poorly standardized. EVs are heterogeneous in size, origin and molecular constituents, with considerable overlap in size and phenotype between different populations of EVs. Little is known about current practices for the isolation, purification and characterization of EVs. We report here the first large, detailed survey of current worldwide practices for the isolation and characterization of EVs. Conditioned cell culture media was the most widely used material (83%). Ultracentrifugation remains the most commonly used isolation method (81%) with 59% of respondents use a combination of methods. Only 9% of respondents used only 1 characterization method, with others using 2 or more methods. Sample volume, sample type and downstream application all influenced the isolation and characterization techniques employed. PMID:27802845

  9. Techniques used for the isolation and characterization of extracellular vesicles: results of a worldwide survey.

    PubMed

    Gardiner, Chris; Di Vizio, Dolores; Sahoo, Susmita; Théry, Clotilde; Witwer, Kenneth W; Wauben, Marca; Hill, Andrew F

    2016-01-01

    Extracellular vesicles (EVs) represent an important mode of intercellular communication. Research in this field has grown rapidly in the last few years, and there is a plethora of techniques for the isolation and characterization of EVs, many of which are poorly standardized. EVs are heterogeneous in size, origin and molecular constituents, with considerable overlap in size and phenotype between different populations of EVs. Little is known about current practices for the isolation, purification and characterization of EVs. We report here the first large, detailed survey of current worldwide practices for the isolation and characterization of EVs. Conditioned cell culture media was the most widely used material (83%). Ultracentrifugation remains the most commonly used isolation method (81%) with 59% of respondents use a combination of methods. Only 9% of respondents used only 1 characterization method, with others using 2 or more methods. Sample volume, sample type and downstream application all influenced the isolation and characterization techniques employed.

  10. Telephone survey to investigate relationships between onychectomy or onychectomy technique and house soiling in cats.

    PubMed

    Gerard, Amanda F; Larson, Mandy; Baldwin, Claudia J; Petersen, Christine

    2016-09-15

    OBJECTIVE To determine whether associations existed between onychectomy or onychectomy technique and house soiling in cats. DESIGN Cross-sectional study. SAMPLE 281 owners of 455 cats in Polk County, Iowa, identified via a list of randomly selected residential phone numbers of cat owners in that region. PROCEDURES A telephone survey was conducted to collect information from cat owners on factors hypothesized a priori to be associated with house soiling, including cat sex, reproductive status, medical history, and onychectomy history. When cats that had undergone onychectomy were identified, data were collected regarding the cat's age at the time of the procedure and whether a carbon dioxide laser (CDL) had been used. Information on history of house soiling behavior (urinating or defecating outside the litter box) was also collected. RESULTS Onychectomy technique was identified as a risk factor for house soiling. Cats for which a non-CDL technique was used had a higher risk of house soiling than cats for which the CDL technique was used. Cats that had undergone onychectomy and that lived in a multicat (3 to 5 cats) household were more than 3 times as likely to have house soiled as were single-housed cats with intact claws. CONCLUSIONS AND CLINICAL RELEVANCE Results of this cross-sectional study suggested that use of the CDL technique for onychectomy could decrease the risk of house soiling by cats relative to the risk associated with other techniques. This and other findings can be used to inform the decisions of owners and veterinarians when considering elective onychectomy for cats.

  11. Survey on Robot-Assisted Surgical Techniques Utilization in US Pediatric Surgery Fellowships.

    PubMed

    Maizlin, Ilan I; Shroyer, Michelle C; Yu, David C; Martin, Colin A; Chen, Mike K; Russell, Robert T

    2017-02-01

    Robotic technology has transformed both practice and education in many adult surgical specialties; no standardized training guidelines in pediatric surgery currently exist. The purpose of our study was to assess the prevalence of robotic procedures and extent of robotic surgery education in US pediatric surgery fellowships. A deidentified survey measured utilization of the robot, perception on the utility of the robot, and its incorporation in training among the program directors of Accreditation Council for Graduate Medical Education (ACGME) pediatric surgery fellowships in the United States. Forty-one of the 47 fellowship programs (87%) responded to the survey. While 67% of respondents indicated the presence of a robot in their facility, only 26% reported its utilizing in their surgical practice. Among programs not utilizing the robot, most common reasons provided were lack of clear supportive evidence, increased intraoperative time, and incompatibility of instrument size to pediatric patients. While 58% of program directors believe that there is a future role for robotic surgery in children, only 18% indicated that robotic training should play a part in pediatric surgery education. Consequently, while over 66% of survey respondents received training in robot-assisted surgical technique, only 29% of fellows receive robot-assisted training during their fellowship. A majority of fellowships have access to a robot, but few utilize the technology in their current practice or as part of training. Further investigation is required into both the technology's potential benefits in the pediatric population and its role in pediatric surgery training.

  12. Use of remote-sensing techniques to survey the physical habitat of large rivers

    USGS Publications Warehouse

    Edsall, Thomas A.; Behrendt, Thomas E.; Cholwek, Gary; Frey, Jeffery W.; Kennedy, Gregory W.; Smith, Stephen B.; Edsall, Thomas A.; Behrendt, Thomas E.; Cholwek, Gary; Frey, Jeffrey W.; Kennedy, Gregory W.; Smith, Stephen B.

    1997-01-01

    Remote-sensing techniques that can be used to quantitatively characterize the physical habitat in large rivers in the United States where traditional survey approaches typically used in small- and medium-sized streams and rivers would be ineffective or impossible to apply. The state-of-the-art remote-sensing technologies that we discuss here include side-scan sonar, RoxAnn, acoustic Doppler current profiler, remotely operated vehicles and camera systems, global positioning systems, and laser level survey systems. The use of these technologies will permit the collection of information needed to create computer visualizations and hard copy maps and generate quantitative databases that can be used in real-time mode in the field to characterize the physical habitat at a study location of interest and to guide the distribution of sampling effort needed to address other habitat-related study objectives. This report augments habitat sampling and characterization guidance provided by Meador et al. (1993) and is intended for use primarily by U.S. Geological Survey National Water Quality Assessment program managers and scientists who are documenting water quality in streams and rivers of the United States.

  13. Use of image guided radiation therapy techniques and imaging dose measurement at Indian hospitals: A survey

    PubMed Central

    Deshpande, Sudesh; Dhote, D. S.; Kumar, Rajesh; Naidu, Suresh; Sutar, A.; Kannan, V.

    2015-01-01

    A national survey was conducted to obtain information about the use of image-guided radiotherapy (IGRT) techniques and IGRT dose measurement methods being followed at Indian radiotherapy centers. A questionnaire containing parameters relevant to use of IGRT was prepared to collect the information pertaining to (i) availability and type of IGRT delivery system, (ii) frequency of image acquisition protocol and utilization of these images for different purpose, and (iii) imaging dose measurement. The questionnaire was circulated to 75 hospitals in the country having IGRT facility, and responses of 51 centers were received. Survey results showed that among surveyed hospitals, 86% centers have IGRT facility, 78% centers have kilo voltage three-dimensional volumetric imaging. 75% of hospitals in our study do not perform computed tomography dose index measurements and 89% of centers do not perform patient dose measurements. Moreover, only 29% physicists believe IGRT dose is additional radiation burden to patient. This study has brought into focus the need to design a national protocol for IGRT dose measurement and development of indigenous tools to perform IGRT dose measurements. PMID:26865758

  14. Survey of agents and techniques applicable to the solidification of low-level radioactive wastes

    SciTech Connect

    Fuhrmann, M.; Neilson, R.M. Jr.; Colombo, P.

    1981-12-01

    A review of the various solidification agents and techniques that are currently available or potentially applicable for the solidification of low-level radioactive wastes is presented. An overview of the types and quantities of low-level wastes produced is presented. Descriptions of waste form matrix materials, the wastes types for which they have been or may be applied and available information concerning relevant waste form properties and characteristics follow. Also included are descriptions of the processing techniques themselves with an emphasis on those operating parameters which impact upon waste form properties. The solidification agents considered in this survey include: hydraulic cements, thermoplastic materials, thermosetting polymers, glasses, synthetic minerals and composite materials. This survey is part of a program supported by the United States Department of Energy's Low-Level Waste Management Program (LLWMP). This work provides input into LLWMP efforts to develop and compile information relevant to the treatment and processing of low-level wastes and their disposal by shallow land burial.

  15. The Steepness Ratio Technique: A New Method to Analyze ROSAT All-Sky Survey Extended Sources

    NASA Astrophysics Data System (ADS)

    De Grandi, S.; Molendi, S.; Böhringer, H.; Chincarini, G.; Voges, W.

    1997-09-01

    In this first paper of a series we develop a new technique to analyze clusters of galaxies observed during the ROSAT All-Sky Survey (RASS). We call this method the steepness ratio technique (SRT). The SRT uses the convolution between the real RASS point-spread function and the cluster emission profile assumed to be a β model with the β parameter fixed to the value of 2/3. From the convolved source emission profile the SRT extracts total flux and extension (i.e., core radius) for each cluster. Using the steepness ratio (SR) and a control sample of RASS pointlike sources, we are able to assign to each RASS source a model-independent probability of extension. Potential biases arising from the hypotheses of a β-model emission profile and from a fixed β value are quantified. Tests with control samples of optically identified sources extracted from both the ROSAT survey database and from the ROSAT-PSPC pointed observations archive are performed to check the SRT output. We find that the source properties derived using the SRT on RASS data are consistent with those determined from ROSAT-PSPC pointed observations.

  16. Federal laboratory nondestructive testing research and development applicable to industry

    SciTech Connect

    Smith, S.A.; Moore, N.L.

    1987-02-01

    This document presents the results of a survey of nondestructive testing (NDT) and related sensor technology research and development (R and D) at selected federal laboratories. Objective was to identify and characterize NDT activities that could be applied to improving energy efficiency and overall productivity in US manufacturing. Numerous federally supported R and D programs were identified in areas such as acoustic emissions, eddy current, radiography, computer tomography and ultrasonics. A Preliminary Findings Report was sent to industry representatives, which generated considerable interest.

  17. Nondestructive verification and assay systems for spent fuels. Technical appendixes

    SciTech Connect

    Cobb, D.D.; Phillips, J.R.; Baker, M.P.

    1982-04-01

    Six technical appendixes are presented that provide important supporting technical information for the study of the application of nondestructive measurements to spent-fuel storage. Each appendix addresses a particular technical subject in a reasonably self-contained fashion. Appendix A is a comparison of spent-fuel data predicted by reactor operators with measured data from reprocessors. This comparison indicates a rather high level of uncertainty in previous burnup calculations. Appendix B describes a series of nondestructive measurements at the GE-Morris Operation Spent-Fuel Storage Facility. This series of experiments successfully demonstrated a technique for reproducible positioning of fuel assemblies for nondestructive measurement. The experimental results indicate the importance of measuring the axial and angular burnup profiles of irradiated fuel assemblies for quantitative determination of spent-fuel parameters. Appendix C is a reasonably comprehensive bibliography of reports and symposia papers on spent-fuel nondestructive measurements to April 1981. Appendix D is a compendium of spent-fuel calculations that includes isotope production and depletion calculations using the EPRI-CINDER code, calculations of neutron and gamma-ray source terms, and correlations of these sources with burnup and plutonium content. Appendix E describes the pulsed-neutron technique and its potential application to spent-fuel measurements. Although not yet developed, the technique holds the promise of providing separate measurements of the uranium and plutonium fissile isotopes. Appendix F describes the experimental program and facilities at Los Alamos for the development of spent-fuel nondestructive measurement systems. Measurements are reported showing that the active neutron method is sensitive to the replacement of a single fuel rod with a dummy rod in an unirradiated uranium fuel assembly.

  18. Cough Augmentation Techniques in the Critically Ill: A Canadian National Survey.

    PubMed

    Rose, Louise; Adhikari, Neill K; Poon, Joseph; Leasa, David; McKim, Douglas A

    2016-10-01

    Critically ill mechanically ventilated patients experience impaired airway clearance due to ineffective cough and impaired secretion mobilization. Cough augmentation techniques, including mechanical insufflation-exsufflation (MI-E), manually assisted cough, and lung volume recruitment, improve cough efficiency. Our objective was to describe use, indications, contraindications, interfaces, settings, complications, and barriers to use across Canada. An e-mail survey was sent to nominated local survey champions in eligible Canadian units (ICUs, weaning centers, and intermediate care units) with 4 telephone/e-mail reminders. The survey response rate was 157 of 238 (66%); 78 of 157 units (50%) used cough augmentation, with 50 (64%) using MI-E, 53 (68%) using manually assisted cough, and 62 (79%) using lung volume recruitment. Secretion clearance was the most common indication (MI-E, 92%; manually assisted cough, 88%; lung volume recruitment, 76%), although the most common units (44%) used it <50% of the time. Use during weaning from invasive (MI-E, 21%; manually assisted cough, 39%; lung volume recruitment, 3%) and noninvasive ventilation (MI-E, 21%; manually assisted cough, 33%; lung volume recruitment, 21%) was infrequent. The most common diagnoses were neuromuscular disease (97%) and spinal cord injury (83%). Pneumothorax was the most frequently identified absolute contraindication for MI-E (93%) and lung volume recruitment (83%); rib fracture was most frequently identified for manually assisted cough (69%). MI-E mean inspiratory pressure was 31 cm H2O, and expiratory pressure was -32 cm H2O. Mucus plugging requiring tracheostomy inner change was the most frequent complication for MI-E (23%), chest pain for manually assisted cough (36%), and hypotension for lung volume recruitment (17%). The most commonly cited barriers were lack of expertise (70%), knowledge (65%), and resources (52%). We found moderate adoption of cough augmentation techniques, particularly for

  19. Reconstructive techniques in transoral robotic surgery for head and neck cancer: a North American survey.

    PubMed

    Konofaos, Petros; Hammond, Sarah; Ver Halen, Jon P; Samant, Sandeep

    2013-02-01

    Although the use of transoral robotic surgery for tumor extirpation is expanding, little is known about national trends in the reconstruction of resultant defects. An 18-question electronic survey was created by an expert panel of surgeons from the Department of Otolaryngology-Head and Neck Surgery and the Department of Plastic and Reconstructive Surgery at the University of Tennessee. Eligible participants were identified by the American Head and Neck Society Web site and from the Intuitive Surgical, Inc., Web site after review of surgeons trained in transoral robotic surgery techniques. Twenty-three of 27 preselected head and neck surgeons (85.18 percent) completed the survey. All respondents use transoral robotic surgery for head and neck tumor extirpation. The majority of the respondents [n = 17 (77.3 percent)] did not use any means of reconstruction. With respect to methods of reconstruction following transoral robotic surgery defects, the majority [n = 4 (80.0 percent)] used a free flap, a pedicled local flap [n = 3 (60.0 percent)], or a distant flap [n = 3 (60.0 percent)]. The radial forearm flap was the most commonly used free flap by all respondents. In general, the majority of survey respondents allow defects to heal secondarily or close primarily. Based on this survey, consensus indications for pedicled or free tissue transfer following transoral robotic surgery defects were primary head and neck tumors (stage T3 and T4a), pharyngeal defects with exposure of vital structures, and prior irradiation or chemoradiation to the operative site and neck.

  20. Epidemiological survey of different clinical techniques of orthodontic bracket debonding and enamel polishing

    PubMed Central

    Sfondrini, Maria Francesca; Scribante, Andrea; Fraticelli, Danilo; Roncallo, Silvia; Gandini, Paola

    2015-01-01

    Objectives: To conduct an epidemiological survey of the orthodontic debonding techniques in Italy, and describe the most commonly used methods to remove the brackets and adhesive from the tooth surfaces. Materials and Methods: A survey consisting of 6 questions about bracket debonding methods and instruments used was emailed to 1000 orthodontists, who were members of the Italian Orthodontics Society (SIDO. Clinicians were characterized by different sex, age, origin, and professional experience. Results: Overall, 267 surveys were returned, representing a response rate of 26.7% of the participants interviewed. The 0.2% of the orthodontists responded, via email, confirming that they were not interested, while 3% of the questionnaires were sent back not completed. The 70.1% of the clinicians interviewed did not return any response. Overall, 64% of SIDO members (orthodontists) did not detect any enamel damage after debonding. The brackets used most frequently (89.14%) in clinical practice were the metal ones. The most commonly used pliers for bracket removal were cutters (37.08%) and bracket removal pliers (34.83%). For adhesive removal, low speed tungsten carbide burs under irrigation were the most widely utilized method for adhesive removal (40.08%), followed by high speed carbide burs (14.19%), and diamond burs (14.19%). The most frequently used instruments for polishing after debonding were rubber cups (36.70%) and abrasive discs (21.35%). The 31.21% of the orthodontists found esthetic enamel changes before bonding versus after debonding. Conclusions: This survey showed the high variability of different methods for bracket debonding, adhesive removal, and tooth polishing. The collected answers indicate that most orthodontists have developed their own armamentarium of debonding and polishing, basing their method on trials and errors. PMID:26952141

  1. The use of infrared thermography for nondestructive evaluation of joints

    NASA Astrophysics Data System (ADS)

    Meola, Carosena; Carlomagno, Giovanni M.; Squillace, Antonino; Giorleo, Giuseppe

    2004-12-01

    A junction between two similar, or dissimilar, materials represents generally a weak structural point and so it requires accurate choice of the most adequate joining technique and nondestructive evaluation of joined parts whatever the joining technique. The attention of the present paper is focused on the aid provided by infrared thermography for nondestructive evaluation of three types of joints: aluminum adhesively bonded joints, stainless steel laser welded joints and Glare ® mechanical fastened joints. Both techniques, pulse and modulated thermography with optical stimulation, are used. The attention is particularly focused on the second method because phase images are practically not affected by local nonuniform heating and/or local variation of the emissivity coefficient as thermal images.

  2. [Survey of parental acceptance rate to behavior management techniques used in pediatric dentistry].

    PubMed

    Chen, Xu; Jin, Shi-Fu; Liu, Hong-Bo

    2008-10-01

    To investigate the parental acceptance rate to behavior management techniques (BMT) used in pediatric dentistry. Two hundred and eighty-five subjects (mother or father) were included in this survey. Five behavior management techniques including (1)tell-show-do; (2)voice control; (3)passive restraint; (4)sedation; (5) general anesthesia commonly used in pediatric dentistry were explained to the parents and then filled the questionnaires by either of the parents, including the parental age, gender, educational level and income, The answerer rated their acceptance of each technique using a visual analogue scale (VAS), a continuous scale ranging from 0 to 100mm. The left end represented "completely acceptable" and the right end represented "completely unacceptable". The subjects were instructed to rate the acceptability of each technique by placing a mark on the VAS response line. The acceptability rating of each technique by the subject was determined by measuring the distance between VAS line from the left end to the mark. SPSS10.0 software was used for statistical analysis. VAS measurements were analyzed using a factorial analysis of variance (ANOVA). Student's t test was used to analyze the difference between the acceptance rates for different gender of the answerers. The correlation between independent variables consisted of parental gender, education level, income and behavior management techniques were analyzed using Spearman correlation test. The order of decreasing acceptance rate was as follows, tell-show-do, voice control, sedation, general anesthesia and passive restraint. The difference between each of them was statistically significant (F=215.2,P<0.01). The age and the education level of the parent did not have correlation with the acceptance rate of different BMTS. However, the income of the parents was relevant to the acceptance rate of general anesthesia by Spearman correlation analysis (P<0.01). The acceptance rate of tell-show-do and passive

  3. Nondestructive evaluation of nuclear-grade graphite

    NASA Astrophysics Data System (ADS)

    Kunerth, D. C.; McJunkin, T. R.

    2012-05-01

    The material of choice for the core of the high-temperature gas-cooled reactors being developed by the U.S. Department of Energy's Next Generation Nuclear Plant Program is graphite. Graphite is a composite material whose properties are highly dependent on the base material and manufacturing methods. In addition to the material variations intrinsic to the manufacturing process, graphite will also undergo changes in material properties resulting from radiation damage and possible oxidation within the reactor. Idaho National Laboratory is presently evaluating the viability of conventional nondestructive evaluation techniques to characterize the material variations inherent to manufacturing and in-service degradation. Approaches of interest include x-ray radiography, eddy currents, and ultrasonics.

  4. Nondestructive evaluation of nuclear-grade graphite

    SciTech Connect

    Kunerth, D. C.; McJunkin, T. R.

    2012-05-17

    The material of choice for the core of the high-temperature gas-cooled reactors being developed by the U.S. Department of Energy's Next Generation Nuclear Plant Program is graphite. Graphite is a composite material whose properties are highly dependent on the base material and manufacturing methods. In addition to the material variations intrinsic to the manufacturing process, graphite will also undergo changes in material properties resulting from radiation damage and possible oxidation within the reactor. Idaho National Laboratory is presently evaluating the viability of conventional nondestructive evaluation techniques to characterize the material variations inherent to manufacturing and in-service degradation. Approaches of interest include x-ray radiography, eddy currents, and ultrasonics.

  5. A survey on acoustic signature recognition and classification techniques for persistent surveillance systems

    NASA Astrophysics Data System (ADS)

    Shirkhodaie, Amir; Alkilani, Amjad

    2012-06-01

    Application of acoustic sensors in Persistent Surveillance Systems (PSS) has received considerable attention over the last two decades because they can be rapidly deployed and have low cost. Conventional utilization of acoustic sensors in PSS spans a wide range of applications including: vehicle classification, target tracking, activity understanding, speech recognition, shooter detection, etc. This paper presents a current survey of physics-based acoustic signature classification techniques for outdoor sounds recognition and understanding. Particularly, this paper focuses on taxonomy and ontology of acoustic signatures resulted from group activities. The taxonomy and supportive ontology considered include: humanvehicle, human-objects, and human-human interactions. This paper, in particular, exploits applicability of several spectral analysis techniques as a means to maximize likelihood of correct acoustic source detection, recognition, and discrimination. Spectral analysis techniques based on Fast Fourier Transform, Discrete Wavelet Transform, and Short Time Fourier Transform are considered for extraction of features from acoustic sources. In addition, comprehensive overviews of most current research activities related to scope of this work are presented with their applications. Furthermore, future potential direction of research in this area is discussed for improvement of acoustic signature recognition and classification technology suitable for PSS applications.

  6. Repair vs replacement of direct composite restorations: a survey of teaching and operative techniques in Oceania.

    PubMed

    Brunton, Paul A; Ghazali, Amna; Tarif, Zahidah H; Loch, Carolina; Lynch, Christopher; Wilson, Nairn; Blum, Igor R

    2017-04-01

    To evaluate the teaching and operative techniques for the repair and/or replacement of direct resin-based composite restorations (DCRs) in dental schools in Oceania. A 14-item questionnaire was mailed to the heads of operative dentistry in 16 dental schools in Oceania (Australia, New Zealand, Fiji and Papua New Guinea). The survey asked whether the repair of DCRs was taught within the curriculum; the rationale behind the teaching; how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability, expected longevity and recall systems. All 16 schools participated in the study. Thirteen (81%) reported the teaching of composite repairs as an alternative to replacement. Most schools taught the theoretical and practical aspects of repair at a clinical level only. All 13 schools (100%) agreed on tooth substance preservation being the main reason for teaching repair. The main indications for repair were marginal defects (100%), followed by secondary caries (69%). All 13 schools that performed repairs reported high patient acceptability, and considered it a definitive measure. Only three schools (23%) claimed to have a recall system in place following repair of DCRs. Most respondents either did not know or did not answer when asked about the longevity of DCRs. Repair of DCRs seems to be a viable alternative to replacement, which is actively taught within Oceania. Advantages include it being minimally invasive, preserving tooth structure, and time and money saving. However, standardised guidelines need to be developed and further clinical long-term studies need to be carried out. The decision between replacing or repairing a defective composite restoration tends to be based on what clinicians have been taught, tempered by experience and judgement. This study investigated the current status of teaching and operative techniques of repair of direct composite restorations in dental schools in Oceania. Copyright © 2017 Elsevier Ltd

  7. Worldwide Enucleation Techniques and Materials for Treatment of Retinoblastoma: An International Survey

    PubMed Central

    Mourits, Daphne L.; Hartong, Dyonne T.; Bosscha, Machteld I.; Kloos, Roel J. H. M.; Moll, Annette C.

    2015-01-01

    Purpose To investigate the current practice of enucleation with or without orbital implant for retinoblastoma in countries across the world. Methods A digital survey identifying operation techniques and material used for orbital implants after enucleation in patients with retinoblastoma. Results We received a response of 58 surgeons in 32 different countries. A primary artificial implant is routinely inserted by 42 (72.4%) surgeons. Ten (17.2%) surgeons leave the socket empty, three (5.2%) decide per case. Other surgeons insert a dermis fat graft as a standard primary implant (n=1), or fill the socket in a standard secondary procedure (n=2; one uses dermis fat grafts and one artificial implants). The choice for porous implants was more frequent than for non-porous implants: 27 (58.7%) and 15 (32.6%), respectively. Both porous and non-porous implant types are used by 4 (8.7%) surgeons. Twenty-five surgeons (54.3%) insert bare implants, 11 (23.9%) use separate wrappings, eight (17.4%) use implants with prefab wrapping and two insert implants with and without wrapping depending on type of implant. Attachment of the muscles to the wrapping or implant (at various locations) is done by 31 (53.4%) surgeons. Eleven (19.0%) use a myoconjunctival technique, nine (15.5%) suture the muscles to each other and seven (12.1%) do not reattach the muscles. Measures to improve volume are implant exchange at an older age (n=4), the use of Restylane SQ (n=1) and osmotic expanders (n=1). Pegging is done by two surgeons. Conclusion No (worldwide) consensus exists about the use of material and techniques for enucleation for the treatment of retinoblastoma. Considerations for the use of different techniques are discussed. PMID:25767872

  8. A Brief History of the use of Electromagnetic Induction Techniques in Soil Survey

    NASA Astrophysics Data System (ADS)

    Brevik, Eric C.; Doolittle, James

    2017-04-01

    Electromagnetic induction (EMI) has been used to characterize the spatial variability of soil properties since the late 1970s. Initially used to assess soil salinity, the use of EMI in soil studies has expanded to include: mapping soil types; characterizing soil water content and flow patterns; assessing variations in soil texture, compaction, organic matter content, and pH; and determining the depth to subsurface horizons, stratigraphic layers or bedrock, among other uses. In all cases the soil property being investigated must influence soil apparent electrical conductivity (ECa) either directly or indirectly for EMI techniques to be effective. An increasing number and diversity of EMI sensors have been developed in response to users' needs and the availability of allied technologies, which have greatly improved the functionality of these tools and increased the amount and types of data that can be gathered with a single pass. EMI investigations provide several benefits for soil studies. The large amount of georeferenced data that can be rapidly and inexpensively collected with EMI provides more complete characterization of the spatial variations in soil properties than traditional sampling techniques. In addition, compared to traditional soil survey methods, EMI can more effectively characterize diffuse soil boundaries and identify included areas of dissimilar soils within mapped soil units, giving soil scientists greater confidence when collecting spatial soil information. EMI techniques do have limitations; results are site-specific and can vary depending on the complex interactions among multiple and variable soil properties. Despite this, EMI techniques are increasingly being used to investigate the spatial variability of soil properties at field and landscape scales. The future should witness a greater use of multiple-frequency and multiple-coil EMI sensors and integration with other sensors to assess the spatial variability of soil properties. Data analysis

  9. Environmental monitoring using autonomous vehicles: a survey of recent searching techniques.

    PubMed

    Bayat, Behzad; Crasta, Naveena; Crespi, Alessandro; Pascoal, António M; Ijspeert, Auke

    2017-02-27

    Autonomous vehicles are becoming an essential tool in a wide range of environmental applications that include ambient data acquisition, remote sensing, and mapping of the spatial extent of pollutant spills. Among these applications, pollution source localization has drawn increasing interest due to its scientific and commercial interest and the emergence of a new breed of robotic vehicles capable of operating in harsh environments without human supervision. The aim is to find the location of a region that is the source of a given substance of interest (e.g. a chemical pollutant at sea or a gas leakage in air) using a group of cooperative autonomous vehicles. Motivated by fast paced advances in this challenging area, this paper surveys recent advances in searching techniques that are at the core of environmental monitoring strategies using autonomous vehicles.

  10. A Survey on Terrain Assessment Techniques for Autonomous Operation of Planetary Robots

    NASA Astrophysics Data System (ADS)

    Sancho-Pradel, D. L.; Gao, Y.

    A key challenge in autonomous planetary surface exploration is the extraction of meaningful information from sensor data, which would allow a good interpretation of the nearby terrain, and a reasonable assessment of more distant areas. In the last decade, the desire to increase the autonomy of unmanned ground vehicles (UGVs), particularly in terms of off-road navigation, has significantly increased the interest in the field of automated terrain classification. Although the field is relatively new, its advances and goals are scattered across different robotic platforms and applications. The objective of this paper is to present a survey of the field from a planetary exploration perspective, bringing together the underlying techniques, existing approaches and relevant applications under a common framework. The aim is to provide a comprehensive overview to the newcomer in the field, and a structured reference for the practitioners.

  11. Knowledge based systems: A preliminary survey of selected issues and techniques

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Kavi, Srinu

    1984-01-01

    It is only recently that research in Artificial Intelligence (AI) is accomplishing practical results. Most of these results can be attributed to the design and use of expert systems (or Knowledge-Based Systems, KBS) - problem-solving computer programs that can reach a level of performance comparable to that of a human expert in some specialized problem domain. But many computer systems designed to see images, hear sounds, and recognize speech are still in a fairly early stage of development. In this report, a preliminary survey of recent work in the KBS is reported, explaining KBS concepts and issues and techniques used to construct them. Application considerations to construct the KBS and potential KBS research areas are identified. A case study (MYCIN) of a KBS is also provided.

  12. Assessment of decay in standing timber using stress wave timing nondestructive evaluation tools : a guide for use and interpretation

    Treesearch

    Xiping Wang; Ferenc Divos; Crystal Pilon; Brian K. Brashaw; Robert J. Ross; Roy F. Pellerin

    2004-01-01

    This guide was prepared to assist field foresters in the use of stress wave timing instruments to locate and define areas of decay in standing timber. The first three sections provide background information, the principles of stress wave nondestructive testing, and measurement techniques for stress wave nondestructive testing. The last section is a detailed description...

  13. [Gingival displacement techniques in daily practice. Survey among dental surgeons in Abidjan, Ivory Coast].

    PubMed

    Pesson, D M; Bakou, O D; Didia, E L E; Kouame, A; Blohoua, M R J J; Djeredou, K B

    2015-12-01

    Access to cervical margins allows the practitioner to record the entire cervical margin in order to provide a true copy to the technician. This requires a gingival displacement obtainable by different techniques. This study aimed to assess the implementation of gingival displacement methods prior to impression taking in fixed prosthodontics. This is a descriptive and cross-sectional survey of sample of 71 dentists practising in Abidjan, Ivory Coast; which ran from October 2nd, 2010 to November 14th, 2010. A survey form was administered to dentists. The questionnaire was organised around the following headings: identification of dentists and practice of gingival displacement methods. The data processing done using software Epi Info 6 and Excel XP on Window XP, allowed calculation of frequencies, means and proportions and the establishment of connection between variables with the chi2 test. The significance level was set at p < 0.05. The results of the survey indicate that non-surgical methods of gingival displacement, including retraction cords and temporary crowns are those they use most frequently (76.4%) because the vast majority of practitioners (87.22%) believe the most traumatic to the periodontium are surgical methods. Our study showed that the gingival displacement methods are frequently carried out in daily practice, regardless of the topography of the abutment teeth and their number, but with a preference for non-surgical methods, particularly those using retraction cords and temporary crowns. The use of injectable gingival displacement paste is not harmful to the periodontal tissues, easy to use and have a very efficient haemostatic action. It should also be known and practiced.

  14. Analgesic techniques in minor painful procedures in neonatal units: a survey in northern Italy.

    PubMed

    Codipietro, Luigi; Bailo, Elena; Nangeroni, Marco; Ponzone, Alberto; Grazia, Giuseppe

    2011-01-01

    The aim of this survey was to evaluate the current practice regarding pain assessment and pain management strategies adopted in commonly performed minor painful procedures in Northern Italian Neonatal Intensive Care Units (NICUs). A multicenter survey was conducted between 2008 and 2009 in 35 NICUs. The first part of the survey form covered pain assessment tools, the timing of analgesics, and the availability of written guidelines. A second section evaluated the analgesic strategies adopted in commonly performed painful procedures. The listed analgesic procedures were as follows: oral sweet solutions alone, non-nutritive sucking (NNS) alone, a combination of sweet solutions and NNS, breast-feeding where available, and topical anesthetics. Completed questionnaires were returned from 30 neonatal units (85.7% response rate). Ten of the 30 NICUs reported using pain assessment tools for minor invasive procedures. Neonatal Infant Pain Scale was the most frequently used pain scale (60%). Twenty neonatal units had written guidelines directing pain management practices. The most frequently used procedures were pacifiers alone (69%), followed by sweet-tasting solutions (58%). A 5% glucose solution was the most frequently utilized sweet-tasting solution (76.7%). A minority of NICUs (16.7%) administered 12% sucrose solutions for analgesia and the application of topical anesthetics was found in 27% of NICUs while breast-feeding was performed in 7% of NICUs. This study found a low adherence to national and international guidelines for analgesia in minor procedures: the underuse of neonatal pain scales (33%), sucrose solution administration before heel lance (23.3%), topical anesthetics before venipuncture, or other analgesic techniques. The presence of written pain control guidelines in these regions of Northern Italy increased in recent years (from 25% to 66%). © 2010 World Institute of Pain.

  15. Non-destructive microstructural analysis with depth resolution

    NASA Astrophysics Data System (ADS)

    Zolotoyabko, E.; Quintana, J. P.

    2003-01-01

    A depth-sensitive X-ray diffraction technique has been developed with the aim of studying microstructural modifications in inhomogeneous polycrystalline materials. In that method, diffraction profiles are measured at different X-ray energies varied by small steps. X-rays at higher energies probe deeper layers of material. Depth-resolved structural information is retrieved by comparing energy-dependent diffraction profiles. The method provides non-destructive depth profiling of the preferred orientation, grain size, microstrain fluctuations and residual strains. This technique is applied to the characterization of seashells. Similarly, energy-variable X-ray diffraction can be used for the non-destructive characterization of different laminated structures and composite materials.

  16. Review of progress in quantitative nondestructive evaluation. Vol. 3B

    SciTech Connect

    Thompson, D.O.; Chimenti, D.E.

    1984-01-01

    This two-book volume constitutes the Proceedings of the Tenth Annual Review of Progress in Quantitative Nondestructive Evaluation held in California in 1983. Topics considered include nondestructive evaluation (NDE) reliability, ultrasonics (probability of detection, scattering, sizing, transducers, signal processing, imaging and reconstruction), eddy currents (probability of detection, modeling, sizing, probes), acoustic emission, thermal wave imaging, optical techniques, new techniques (e.g., maximum entropy reconstruction, near-surface inspection of flaws using bulk ultrasonic waves, inversion and reconstruction), composite materials, material properties, acoustoelasticity, residual stress, and new NDE systems (e.g., retirement-for-cause procedures for gas turbine engine components, pulsed eddy current flaw detection and characterization, an ultrasonic inspection protocol for IN100 jet engine materials, electromagnetic on-line monitoring of rotating turbine-generator components). Basic research and early engineering applications are emphasized.

  17. Shape Sensing Techniques for Continuum Robots in Minimally Invasive Surgery: A Survey.

    PubMed

    Shi, Chaoyang; Luo, Xiongbiao; Qi, Peng; Li, Tianliang; Song, Shuang; Najdovski, Zoran; Fukuda, Toshio; Ren, Hongliang

    2017-08-01

    Continuum robots provide inherent structural compliance with high dexterity to access the surgical target sites along tortuous anatomical paths under constrained environments and enable to perform complex and delicate operations through small incisions in minimally invasive surgery. These advantages enable their broad applications with minimal trauma and make challenging clinical procedures possible with miniaturized instrumentation and high curvilinear access capabilities. However, their inherent deformable designs make it difficult to realize 3-D intraoperative real-time shape sensing to accurately model their shape. Solutions to this limitation can lead themselves to further develop closely associated techniques of closed-loop control, path planning, human-robot interaction, and surgical manipulation safety concerns in minimally invasive surgery. Although extensive model-based research that relies on kinematics and mechanics has been performed, accurate shape sensing of continuum robots remains challenging, particularly in cases of unknown and dynamic payloads. This survey investigates the recent advances in alternative emerging techniques for 3-D shape sensing in this field and focuses on the following categories: fiber-optic-sensor-based, electromagnetic-tracking-based, and intraoperative imaging modality-based shape-reconstruction methods. The limitations of existing technologies and prospects of new technologies are also discussed.

  18. Search Techniques for the Web of Things: A Taxonomy and Survey

    PubMed Central

    Zhou, Yuchao; De, Suparna; Wang, Wei; Moessner, Klaus

    2016-01-01

    The Web of Things aims to make physical world objects and their data accessible through standard Web technologies to enable intelligent applications and sophisticated data analytics. Due to the amount and heterogeneity of the data, it is challenging to perform data analysis directly; especially when the data is captured from a large number of distributed sources. However, the size and scope of the data can be reduced and narrowed down with search techniques, so that only the most relevant and useful data items are selected according to the application requirements. Search is fundamental to the Web of Things while challenging by nature in this context, e.g., mobility of the objects, opportunistic presence and sensing, continuous data streams with changing spatial and temporal properties, efficient indexing for historical and real time data. The research community has developed numerous techniques and methods to tackle these problems as reported by a large body of literature in the last few years. A comprehensive investigation of the current and past studies is necessary to gain a clear view of the research landscape and to identify promising future directions. This survey reviews the state-of-the-art search methods for the Web of Things, which are classified according to three different viewpoints: basic principles, data/knowledge representation, and contents being searched. Experiences and lessons learned from the existing work and some EU research projects related to Web of Things are discussed, and an outlook to the future research is presented. PMID:27128918

  19. Search Techniques for the Web of Things: A Taxonomy and Survey.

    PubMed

    Zhou, Yuchao; De, Suparna; Wang, Wei; Moessner, Klaus

    2016-04-27

    The Web of Things aims to make physical world objects and their data accessible through standard Web technologies to enable intelligent applications and sophisticated data analytics. Due to the amount and heterogeneity of the data, it is challenging to perform data analysis directly; especially when the data is captured from a large number of distributed sources. However, the size and scope of the data can be reduced and narrowed down with search techniques, so that only the most relevant and useful data items are selected according to the application requirements. Search is fundamental to the Web of Things while challenging by nature in this context, e.g., mobility of the objects, opportunistic presence and sensing, continuous data streams with changing spatial and temporal properties, efficient indexing for historical and real time data. The research community has developed numerous techniques and methods to tackle these problems as reported by a large body of literature in the last few years. A comprehensive investigation of the current and past studies is necessary to gain a clear view of the research landscape and to identify promising future directions. This survey reviews the state-of-the-art search methods for the Web of Things, which are classified according to three different viewpoints: basic principles, data/knowledge representation, and contents being searched. Experiences and lessons learned from the existing work and some EU research projects related to Web of Things are discussed, and an outlook to the future research is presented.

  20. Liquid crystals in nondestructive testing.

    PubMed

    Fergason, J L

    1968-09-01

    The cholesteric phase is associated with scattering effects that give rise to iridescent colors, the dominant wavelength being influenced by very small changes in temperature, which can be as large as 1000 A shift per degree. This unusually high temperature sensitivity has given rise to the use of the cholesteric phase as a sensitive thermometer and thermal mapping media. This paper reviews the optical effects in the cholesteric phase with some new additions that are particularly relevant to thermal mapping. An attempt has been made to give a complete picture of the cholesteric liquid crystal as applied to nondestructive testing, rather than to review the work actually being done in this field.